According to the Stoics, only physical stuff exists.1 To describe it in theirterms, the world consists of different types of an airy substance, pneuma.Some of these pneumatic stuffs instantiate psychological properties orstates. Thus, psychological attributes, which they deny are completely different in kind from bodily properties, can be studied as part of the natural world.2 Within the context of their naturalism, the Stoics also carefully attend to the character of psychological properties. Despite theirdifferences, such states as sense-perceptions, emotions, and beliefs conveyinformation to an agent. The complex physical organization of the under-lying pneumatic states determines why such psychological states havecontent. Thus, the Stoics aim to provide a uni� ed theory of varied mentalphenomena.3
Accepted March 19971 There are ontological complications since they also hold that there are things that
do not exist, such as sayables (lekta). See, e.g., Sextus M 10. 218. 2 Though the Stoics reject ordinary versions of substance dualism, their own views
are complicated in ways I shall not explore. In particular, they do not appear to accepteither a version of reductive type-physicalism in which psychological states are sim-ply identi� ed with physical ones, or eliminativist theories. The Stoics are committedto nothing more than that psychological properties have a physical basis suf� cient fortheir real existence and their explanation. Accordingly, all that can be said here is thatthe Stoics endorse some weak version of non-reductive physicalism. One apparent dissent from this view is Deborah Modrak, ÒStoics, Epicureans and Mental Content,ÓApeiron 26 (1993), p. 98, which is a review-discussion of Julia Annas, HellenisticPhilosophy of Mind (Berkeley: University of California Press, 1992). Modrak suggestswithout argument that Stoic monism about the world provides a motive for a reduc-tive physicalism. David Sedley, ÒChrysippus on psychophysical causality,Ó Passionsand Perceptions: Studies in Hellenistic Philosophy of Mind (Cambridge: CambridgeUniversity Press, 1993), edd. Jacques Brunschwig and Martha C. Nussbaum, pp. 313-331, argues that it is a mistake to understand Chrysippus to distinguish distinctly phys-ical from mental descriptions of psychological attributes. The basic Stoic texts andtheir fundamental arguments on behalf of their view are clearly presented in JuliaAnnas, Hellenistic Philosophy of Mind, pp. 3-6, 20-33, 37-70.
3 These general remarks help to reveal the attraction of Stoic philosophy of mindfor many contemporary scholars. The Stoics are thoroughgoing naturalists who con-duct a serious inquiry into the ascription of propositional attitudes. Their analysis of fundamental issues in philosophy of mind is often subtle and serves to remind
It quickly becomes evident that the Stoic view about the nature andextent of the propositional content of mental states is puzzling. They denythat human young or animals can entertain beliefs or have thoughts. Theexistence of propositional attitudes ordinarily is held to involve the attri-bution of some thought or belief. So, it would follow that the Stoics denysmall children or animals have mental states with propositional contents.Yet, there is also evidence to the contrary. For instance, in his well-knownexample, Chrysippus attributes what appears to be reasoning by disjunc-tive syllogism to a dog. One might argue that this kind of example com-mits the Stoics to the ascription of propositional contents even in the caseof animals. Furthermore, if the mental states of non-rational animals areso impoverished as to lack any propositional content, the Stoics mustexplain how it is possible for such animals to function adequately at all.DoesnÕt, say, a mouse see that a cat is nearby? Recently, commentatorshave debated the extent of propositional contents in the Stoic account ofpsychological states. The discussion has focused, in particular, on per-ceptional states because for the Stoics perception and impulse are whatdistinguish animal life from other living things and perception has a spe-cial prominence in their inquiry into mental states. Two basic, competinginterpretations have emerged. On what has become the orthodox reading,the Stoics sharply separate the psychological states of non-rational ani-mals from those of rational animals. According to advocates of the ortho-dox position, the mental states of, say, small children are too simple tohave the cognitive structure necessary for the attribution of propositionalattitudes to them.4 Non-rational animals can perceive only qualities such
scholars of contemporary discussions. Here are just two examples. While Julia Annas,Hellenistic Philosophy of Mind, does not discover the ancestor of any particular con-temporary position in Stoic thought, she does suggest, e.g., pp. 1-2, that the Stoicsconstruct the � rst philosophy of mind that is recognizably contemporary. Richard Sorabji, ÒPerceptual Content in the Stoics,Ó Phronesis 35 (1990), pp. 307-314, goesmuch further. He argues that the Stoics would endorse the basic views of DanielDennett on propositional attitudes rather than those of Donald Davidson.
4 Michael Frede, ÒStoics and Skeptics on Clear and Distinct Impressions,Ó TheSkeptical Tradition (Berkeley: University of California Press, 1983), ed. Myles Burnyeat,pp. 65-93, is among the clearest and most forceful proponents of this view. Othersinclude Brad Inwood, Ethics and Human Action in Early Stoicism (Oxford: OxfordUniversity Press, 1985), pp. 73-75, A.A. Long and D.N. Sedley, The HellenisticPhilosophers , vol. 1 (Cambridge: Cambridge University Press, 1987), pp. 239-241,Christopher Gill, ÒIs there a concept of person in Greek philosophy?,Ó Companions toancient thought 2: Psychology (Cambridge: Cambridge University Press, 1991), ed.Stephen Everson, pp. 166-193, and Jean-Louis Labarri� re, ÒDe la Ônature phantastiqueÕ
2 GLENN LESSES
as sweetness or whiteness. According the second interpretation, the Stoicsdeny that the sensory perceptions of animals are completely devoid of pro-positional contents. On this alternative reading, the Stoics much more liberally ascribe propositional content even in the case of non-rational animals.5
In this essay, I argue that the Stoics draw some distinctions – as theyoften are prone to do – that, as a result, enable us to locate a solution tothe puzzle. The Stoics deny that there are any raw psychological statescompletely devoid of cognitive content because they discriminate betweena conception of more robust and more narrow content. It follows that theStoics occupy an intermediate position, less severe than what the orthodoxinterpretation attributes to them and less generous than what the alterna-tive account � nds. Thus, the Stoics hold that there is considerable conti-nuity as well as signi� cant differences between the psychological states ofrational and non-rational animals.
I
Several basic features of Stoic psychological theory are relevant to issuesabout content. The early Stoics speak of psuch¶ in two senses (Sextus M 7. 234).6 The term often is used to include many of the ways in which
des animaux chez les Sto�ciens,Ó Passions and Perceptions: Studies in HellenisticPhilosophy of Mind (Cambridge: Cambridge University Press, 1993), edd. JacquesBrunschwig and Martha C. Nussbaum, 225-249.
5 Richard Sorabji is the principal advocate of this interpretation. See his ÒPercep-tual Content in the Stoics,Ó pp. 307-314, ÒIntentionality and Physiological Processes:AristotleÕs Theory of Sense-Perception,Ó Essays on AristotleÕs De Anima (Oxford: OxfordUniversity Press, 1992), edd. Martha C. Nussbaum and Am� lie Oksenberg Rorty, espe-cially, pp. 195-206, ÒAnimal Minds,Ó Spindel Conference 1992: Ancient Minds, ed.John Ellis, The Southern Journal of Philosophy 31 (1993), supplement, especially, pp.1-12, Animal Minds and Human Morals: The Origins of the Western Debate (Ithaca,New York: Cornell University Press, 1993), pp. 20-28, 40-44. Although Julia Annas,Hellenistic Philosophy of Mind, pp. 75-87, of� cially adopts a version of the orthodoxinterpretation, she also occasionally attributes a kind of content to animal perceptions,pp. 57-64, 71-72. At one point, p. 64, Annas says: ÒHence there is a division of kindbetween animal and human inner life. And hence the Stoics denied to animals not onlyreasoning but emotions and even desires; since animals cannot articulate and interpretin language the content of their experience. . . .Ó Does she hold that non-rational sen-sory perceptions have propositional contents that animals are unable to verbalize? Ifso, her position ascribes content to the impressions of non-rational animals and appearsvery close to what Sorabji formulates more fully.
6 The positions formulated by Zeno, Cleanthes, and, especially, Chrysippus consti-
CONTENT, CAUSE, AND STOIC IMPRESSIONS 3
both rational and non-rational animals function.7 The pneumatic substanceconstituting the soul, understood this way, is intimately blended with thesomewhat different pneuma of a body to form a living animal. Yet, inanother sense, the Stoics often refer to just one part of the soul, namely,its ruling part (to h¶gemonikon). This part is restricted to those activitieswe typically regard as mental – thinking, believing, perceiving, and soforth – rather than the entire range of living functions. Both rational andnon-rational animals have a ruling part of the soul, though non-rationalanimals cannot entertain thoughts or desires. When another part of thesoul is affected, such as in the case of sense-perception, it also producesalterations in the ruling part.8 Since the ruling part of the soul is the loca-tion of desire and reason in rational animals and activities such as sense-perception also affect it,9 it is particularly easy for the Stoics to speakloosely – as they often do – and identify the soul with the ruling part. Ishall restrict my use of ÒsoulÓ to the notion of the soulÕs ruling aspect andusually apply ÒmindÓ or ÒmentalÓ to describe it.
Central to whether the Stoics hold that mental events have content istheir view of perception (aisth¶sis). Ordinary perceptual events have twoconceptually distinct stages: phantasia and assent (sunkatathesis ). Al-though phantasia is often translated as Òappearance,Ó the term refers to abasic, representational mental state, which includes much more than visualappearances. 10 The Stoic notion of phantasia applies to other mental func-tions besides sense-perception. For instance, the h¶gemonikon can gener-ate non-perceptual phantasiai through its own internal operations (D.L. 7. 51). Something more neutral such as ÒimpressionÓ captures the termÕswider range.11
tute orthodox Stoicism. As is well-known, later Stoics such as Panaetius appear tomodify or reject several central tenets of early Stoicism about the soul.
7 Julia Annas, Hellenistic Philosophy of Mind, p. 54, points out that in Stoic theorysome capacities of living things such as basic metabolism are not part of the soulÕsfunctions.
8 See Calcidius in Tim. 220, Aetius 4. 21. 1-3, Plotinus 4. 7. 7.9 See Stobaeus 1. 368. 12-15, Aetius 4. 23. 1.
10 It is helpful to survey the considerable scholarship about AristotleÕs concep-tion of phantasia. Two useful sources are: Martha Nussbaum, AristotleÕs De MotuAnimalium (Princeton: Princeton University Press, 1978), pp. 221-269, for a generaldiscussion of Aristotle on phantasia, and Brad Inwood, Ethics and Human Action inEarly Stoicism, for a succinct account of the general Aristotelian background for theStoics, pp. 9-17.
11 Although phantasia is, of course, legitimately translated as ÒappearanceÓ becauseit derives from the verb Òto appearÓ and is just the way things appear to one, this ren-
4 GLENN LESSES
The Stoics often describe a phantasia as a kind of imprint (tup¬sis).12
Although this imprint is something physical, the Stoics debated exactlyhow one should construe it:
(1) We shall know this if we � rst learn what impression is, according to them, andwhat its speci� c differentiae are. So, according to them, an impression is an imprint (tup¬sis) in the soul. And they differed immediately about this. For Cleanthestook imprint in terms of depression and elevation – just like the imprint on waxmade by seal-rings. But Chrysippus thought that such a view was absurd. For� rst, he says, this will require that when our intellect has impressions at one timeof a triangle and a tetragon, the same body will have to have in itself at the sametime different shapes – triangular and tetragonal together, or even round; whichis absurd. Next, since many imprints exist in us at the same time the soul willalso have many con� gurations. This is worse than the � rst problem. [Chrysippus]himself speculated, therefore, that imprint was used by Zeno to mean alteration;so that the de� nition becomes like this: Òimpression is an alteration of the soulÓ;for it is no longer absurd that the same body at one and the same time (whenmany impressions exist in us) should receive many alterations. For just as air,when many people speak at once, receiving at one time an inde� nite number ofdifferent blows, also has many alterations, so too the ruling part of the soul willexperience something similar when it receives varied impressions.13 [Sextus, M 7. 227-231]
Both Cleanthes and Chrysippus share the view that an impression is some-thing physical, namely, a modi� cation of some pneuma. They disagreeabout how to explain this physical change, but both rule out treating
dering might misleadingly suggest that it primarily involves visual images and thesense-modality of sight. Michael Frede, ÒStoics and Skeptics on Clear and DistinctImpressions,Ó and A.A. Long and D.N. Sedley, The Hellenistic Philosophers, vol. 1,employ Òimpression.Ó Various other attempts to render the term include: Julia Annas,Hellenistic Philosophy of Mind, and Richard Sorabji, ÒPerceptual Content in theStoics,Ó use Òappearance,Ó Brad Inwood and L.P. Gerson, Hellenistic Philosophy:Introductory Readings (Indianapolis: Hackett Publishing Co., 1988), Òpresentation,Ó(which also has the virtue of neutrality with respect to sense-modalities, but doesnÕtre� ect the de� nition of phantasia in terms of tup¬sis quite as well) and A.A. Long,ÒRepresentation and the self in Stoicism,Ó Companions to Ancient Thought 2: Psy-chology (Cambridge: Cambridge University Press, 1991), ed. Stephen Everson, pp.102-120, uses Òrepresentation.Ó A.A. Long, p. 107, n. 6, changes his usage from hisearlier ÒimpressionÓ to ÒrepresentationÓ because he worries that the Humean associa-tions of ÒimpressionÓ might mislead.
12 See D.L. 7. 50, Sextus M 7. 227-231, 7. 372-373, Plut. Ad Col. 1122C, Comm.not. 1084F.
13 See also D.L. 7. 45-46, 50. Unless otherwise indicated, translations are based onBrad Inwood and L.P. Gerson, Hellenistic Philosophy: Introductory Readings, withoccasional modi� cations.
CONTENT, CAUSE, AND STOIC IMPRESSIONS 5
impression solely as a kind of image.14 Furthermore, both Cleanthes andChrysippus attempt to explain phantasia in terms of the complexity of itsphysical structure. Chrysippus rejects what he takes to be CleanthesÕ viewthat an adequate explanation of an agentÕs impressions must attribute the same qualitative features to the impression as to that which theyrepresent.15
The second stage involved in perception proper is assent (sunkata-thesis). For perception to occur, an agent must not only be presented withan impression, he or she also must assent to it.16 In rational animals, assentto an impression is a voluntary act.17 The Stoics often speak of sunkata-
14 For discussions of this passage in Sextus, see Julia Annas, Hellenistic Philosophyof Mind, pp. 72-75, Deborah Modrak, ÒStoics, Epicureans, and Mental Content,Ó p. 99, A.A. Long and D.N. Sedley, The Hellenistic Philosophers, vol. 1, p. 239, andDavid Sedley, ÒChrysippus on psychophysical causality,Ó pp. 329-330. According toModrak, the passage suggests that Chrysippus does not accept that an impression isan imprint. But the text indicates that the dispute between Chrysippus and Cleanthesover what Zeno meant is instead a matter of interpreting the nature of a tup¬sis. Bothappear to accept that an impression is an imprint of some kind.
15 Julia Annas, Hellenistic Philosophy of Mind, pp. 74-75, points out Sextus mightnot do justice to the dispute. It is possible that Chrysippus simply attempted to developfurther what he held to be the same fundamental view as CleanthesÕ position.
However, Chrysippus appears to criticize Cleanthes for accepting a naive view ofmental representation that implies that perceptual impressions are copies of the quali-ties that the objects represented have. For instance, on CleanthesÕ account of impres-sion, when we perceive a triangular object the impression that we ordinarily have istriangular. Some commentators have taken the remarks of Chrysippus to entail thatimpressions are propositional in form or articulable in linguistic form. E.g., Annas, pp.74-75, concludes that Chrysippus Òanalyzed perception in terms of the reception ofcontent and its articulation in linguistic form.Ó This conclusion is too strong. All thatseems to follow is that the impression conveys information. Whether what is conveyedrequires propositional content is less clear. Why is it necessary that our perceptualimpressions of, say, squareness or redness, involve the proposition that something isred or square? As it stands, all Chrysippus has to accept is that the qualities thatimpressions have are not necessarily similar to the characteristics of their causes.
16 See D.L. 7. 49, Cicero Acad. 1. 40, 2. 145, Plut. Ad Col. 1122B-C, Stobaeus 1. 349. 23-27.
17 The nature of assent for non-rational animals is a vexed and complicated ques-tion. Brad Inwood, Ethics and Human Action in Early Stoicism, p. 72, denies that non-rational animals can assent. Jean-Louis Labarri� re, ÒDe la Ônature phantastiqueÕ desanimaux chez les Sto�ciens,Ó especially, pp. 243-249, argues that the Stoic position is that animals can exhibit a type of assent to impressions. See also Julia Annas,Hellenistic Philosophy of Mind, pp. 72-75, 89-102, Christopher Gill, ÒIs there a concept of person in Greek philosophy?,Ó pp. 185-186, A.A. Long and D.N. Sedley,The Hellenistic Philosophers, vol. 1, p. 322, A.A. Long, ÒRepresentation and the self
6 GLENN LESSES
thesis resulting in some sort of belief. Much depends on the nature of theimpression to which agents are assenting since assent is a sort of genus.To outline the basic Stoic position, what agents assent to, at least in manycases, is a proposition (lekton) characterized by the impression. Genuinelyconceptual thinking arises subsequently to the occurrence of impressions.18
The Stoics hold that concepts are a type of impression, which results froman agent, in effect, internalizing repeated, similar impressions.19 The actof thinking involves articulating or re� ecting about the proposition towhich one has assented. Although the Stoics distinguish theoretically be-tween the occasion of having an impression and assenting to it, it is un-clear whether the two stages are actually distinct in cases of sense-perception.
II
The basic issues about mental content will become clearer if we comparethe two principal, competing interpretations. The accounts of MichaelFrede and Richard Sorabji are prominent representatives of each. Let me� rst brie� y discuss FredeÕs perspicuous formulation of the orthodox read-ing. According to Frede,20 both non-rational and rational animals have sen-sory capacities that causally connect them with the world around them.Yet, they also differ signi� cantly in the nature of their sense-experience.In particular, the impressions that occur in animals and human young aredifferent in kind from those of adult humans. Mature human beings haverational impressions which are propositional in nature. When Dion seeshis house, his impression is that it is brown, has two � oors, needs to bepainted, and so forth. But a young child, Theon, cannot have these sortsof impressions and perceives only, say, brownness and the characteristicof having two � oors. Infant and animal impressions cannot support thatsomething is the case and thus fail to have any propositional contents at all.21
in Stoicism,Ó pp. 110-111, Richard Sorabji, Animal Minds and Human Morals, pp. 40-42.
18 D.L. 7. 49, Sextus M 8. 56, Galen, Def. med. 19. 381.19 Plut. Comm. not. 1084F-1085A, Aetius 4. 11. 1-5. 20 The summary of FredeÕs interpretation is derived from ÒStoics and Skeptics on
Clear and Distinct Impressions,Ó especially pp. 66-73. 21 Frede also suggests that not all propositional impressions have the same degree
of propositional content. There can be grades of propositional involvement. Further,Frede, ÒStoics and Skeptics on Clear and Distinct Impressions,Ó p. 69, indicates thatwe ought to distinguish the manner in which different impressions are held. Although
CONTENT, CAUSE, AND STOIC IMPRESSIONS 7
What is FredeÕs main evidence? Text (2) leads Frede to hold that anyimpression of a rational being is rational.
(2) Of impressions, some are rational (logikai) and some are non-rational (alogoi).The rational are those of rational animals, the non-rational of non-rational. Therational, then, are thoughts and the non-rational have been given no special name.[D.L. 7. 51]
Because the passage identi� es rational impressions with thoughts, he alsoconcludes that only rational impressions have propositional content.22 Othertexts also sharply distinguish between rational impressions and impres-sions that are merely perceptual:
(3) Through the senses alone one is not able to grasp the truth, as we indicatedbefore23 and now shall explain brie� y, for they [the senses] are by nature non-rational, and of more than being impressed by impressors [i.e., the things thatimpress] they are not capable, as they are completely unsuitable for discoveringthe truth. For not only must one be moved to have a sensation of white or sweetfor one to grasp the truth in the underlying things, but one must be brought tohave an impression of that thing that Òthis is whiteÓ and Òthis is sweet.Ó And sothe other like things [i.e., the other senses]. But to grasp a thing of this kind isno longer the work of perception. For color only and taste and sound is its natureto grasp, while that Òthis is whiteÓ or Òthis is sweet,Ó which are neither color nortaste, is unsuspected by sense.24 [Sextus M 7. 344-345]
Frede identi� es the results of sense-perception in this passage with whatare, according to (2), non-rational impressions. It follows that by the exer-cise of sense-perception alone one would not be able to entertain impres-sions with propositional content. A statement that something is the case
this point is generally less important for our purposes, it is worth noting that for Frederational impressions can give rise to distinct thoughts because otherwise identical im-pressions can be held in different manners. Sameness of content does not completelydetermine identity of thoughts. See also, his ÒThe Stoic doctrine of the affections ofthe soul,Ó The Norms of Nature: Studies in Hellenistic Ethics (Cambridge: CambridgeUniversity Press, 1986), edd. Malcolm Scho� eld and Gisela Striker, especially pp. 103-107.
22 Michael Frede, ÒStoics and Skeptics on Clear and Distinct Impressions,Ó p. 67:ÒRational impressions have a propositional content, they are impressions to the effectthat something is the case very much in the sense in which we might say ordinarily,Ôthe impression, which one gets, if one looks at the evidence, is that. . . .Õ Ó Frede alsoappeals to Galen Def. med. 126 for additional support.
23 See Sextus M 7. 293. 24 The translation is mine.
8 GLENN LESSES
is required for us to determine truth or falsity. But Frede takes (3) to denythat sense-perception itself can supply the requisite propositional form. Atmost, the senses can tell us about the qualities of things – their whiteness,say, or sweetness – when we are causally affected by external things. Thisis all that a tup¬sis, the imprint, can convey in such cases.
In another important passage, Cicero appears to con� rm FredeÕs read-ing and also adds something:
(4) Those characteristics which belong to the things we describe as being grasped bythe senses are equally characteristic of that further set of things said to be graspednot by the senses directly but by them in a certain respect, e.g., Òthat is white,this is sweet, that is melodious, this is fragrant, this is bitter.Ó Our grasp of theseis secured by the mind, not the senses. Next, Òthat is a horse, that is a dog.Ó Therest of the series then follows, connecting bigger items which virtually includecomplete grasp of things, like Òif it is a human being, it is a mortal, rational ani-mal.Ó From this class conceptions of things are imprinted on us, without whichthere can be no understanding or discussion of anything.25 [Acad. 2. 21]
For Frede, (3) indicates that the senses by themselves are unable to pro-duce impressions containing any propositional content. This task, ac-cording to (4), requires certain operations of the mind. Thus, rational andnon-rational animals differ in the sorts of impressions of which they are capable. Frede explains the capacity of rational animals to entertainrational impressions in terms of their ability to form concepts. Lackingany conceptual apparatus, non-rational animals cannot entertain impres-sions having propositional form. In the Stoic account of psychologicaldevelopment, concepts (ennoiai ) arise later than perceptual impressions(Aetius 4. 11. 1-5). The Stoics separate conceptual thinking from the mereoccurrence of perceptual states.
Although FredeÕs formulation of the Stoic account has considerableplausibility, Richard Sorabji rejects the orthodox reading. He challengesboth the philosophical underpinnings of FredeÕs interpretation as well asits textual support. Let us � rst consider SorabjiÕs objection to a philo-sophical argument employed by Frede and next describe his own freshinterpretive proposal. Sorabji is unimpressed by the theoretical argumentthat concepts are necessary for propositional thought. It is a controversialmatter for many contemporary philosophers of mind whether in every casethe employment of concepts is required for propositional attribution.26
25 This translation basically follows A.A. Long and D.N. Sedley, The HellenisticPhilosophers.
26 See Richard Sorabji, ÒPerceptual Content in the Stoics,Ó pp. 308-309, ÒAnimal
CONTENT, CAUSE, AND STOIC IMPRESSIONS 9
Some argue that despite the necessity of concepts for belief-attributionthere is no such requirement for other sorts of mental states. Consider a typical example: agents can perceive a structure as ten-sided withouthaving a concept of ten or any other relevant concepts. Perceptual con-tent for Sorabji only demands a sort of predication – i.e., one thing beinganother.27 Although his conception of propositional content as predicationis never fully explained, let us defer our discussion of it until later. At thispoint, all we need to see is SorabjiÕs strategy for undermining FredeÕsargument about concepts and propositional contents.28
Sorabji also addresses FredeÕs textual arguments. First, Sorabji arguesthat it is consistent with text (2) that non-rational impressions have prop-ositional form. Rational impressions can be a subset of impressions thathave propositional content.29 The passage does not rule out that other im-pressions also have propositional content. Sorabji then suggests that oursources give us reason to distinguish between two types of verbalizablelinguistic form corresponding to impressions. Some phantasiai – rationalimpressions – are articulable by their owners, while others – non-rationalimpressions – are articulable only by non-owners. Although rational agentscan, in principle, articulate the content of their rational impressions, incontrast, an infant, say, cannot verbalize the content of its perceptualimpressions. 30
Minds,Ó p. 6, ÒIntentionality and Physiological Processes,Ó pp. 200-210, and AnimalMinds and Human Morals, pp. 30-31. He refers particularly to the work of Peacockeand Evans who deny that concepts are required for propositional thought on everyoccasion. See Gareth Evans, The Varieties of Reference (Oxford: Oxford UniversityPress, 1982), and Christopher Peacocke, ÒAnalogue Content,Ó Proceedings of theAristotelian Society (1986), supp. vol. 60, pp. 1-17.
27 Richard Sorabji, ÒPerceptual Content in the Stoics,Ó p. 307, Animal Minds andHuman Morals, pp. 12, 21.
28 If the doctrine that content requires conceptual apparatus fails to be settled forcontemporary philosophy, then Sorabji points out it is a mistake to regard it as incon-trovertible for ancient authors. In any case, how far can FredeÕs objection take us?Although any interpretation will be driven by a principle of charity to attribute as plau-sible an account as the evidence allows, it is always worth being reminded that theStoics and other historical � gures are not immune from adopting patently unjusti� edpositions. Hence, even if the thesis that concepts are required for propositional con-tent turns out to be warranted, it still doesnÕt follow without considerable additionalargument that the Stoics realized that it must be so.
29 Richard Sorabji, ÒPerceptual Content in the Stoics,Ó p. 311, Animal Minds andHuman Morals, p. 25.
30 For the moment, let it suf� ce to point out a more natural reading of (2), which issomewhat weaker than FredeÕs yet does not require that we endorse SorabjiÕs strategy.
10 GLENN LESSES
According to Sorabji, many of FredeÕs other important sources shouldalso be read differently. Sorabji tentatively suggests that text (3), SextusM 7. 344-345, does not re� ect genuine Stoic doctrine.31 But even suppos-ing the passage is orthodox Stoicism, Sorabji argues that it together with(4), Cicero Acad. 2. 21, entail that perceptual impressions have content.For, he argues, if it is true that the senses can only perceive in a way,say, that something is white, then such impressions in a way have somepropositional content. Accordingly, a perceptual impression must be Òas of somethingÕs being whiteÓ rather than an impression simply ofwhiteness.32
On SorabjiÕs account, the impressions of, say, a newborn or a cat dohave propositional content in the sense that their impressions present onething to be predicated of another. Our sources also only speak of impres-sions as verbalizable, not actually verbalized.33 To be sure, non-rationalanimals cannot articulate or conceptualize what they perceive. But, Sorabjiargues, it doesnÕt follow that non-rational animals cannot have impres-sions with content solely because their impressions are not verbaliz-able by them. It suf� ces for the attribution of propositional content thatthe verbalizable impressions of non-rational animals can be articulated byother animals that are rational – namely, us.34 He concludes that animals cannot articulate the content of the impressions that arise in perceptionand in other mental functioning, but their impressions have articulablecontent.35
The passage only establishes that not all impressions are to be identi� ed with thoughtsor beliefs. Rational animals alone can have impressions of the latter sort, but the pas-sage simply leaves open whether the attribution of content requires that impressionsare thoughts.
31 Though most commentators accept that Sextus is describing a Stoic position here,it is dif� cult to determine whether in this text Sextus refers to Stoic doctrine becausethere is no explicit attribution of the view to a particular dogmatic school. RichardSorabji, ÒPerceptual Content in the Stoics,Ó pp. 311-312, presents no argument that itcannot be a reference to Stoicism. But it is also not obvious that FredeÕs inferenceabout the passage follows. The fact that the senses can Òonly grasp color, � avor, andsoundÓ doesnÕt tell us exactly what is entailed by such grasping.
32 Richard Sorabji, ÒPerceptual Content in the Stoics,Ó p. 311. 33 See D.L. 7. 49, Aetius 4. 12. 1, Sextus M 7. 244, M 8. 70. 34 Richard Sorabji, ÒPerceptual Content in the Stoics,Ó p. 311, Animal Minds and
Human Morals, pp. 22-23. 35 In support of his interpretation, Sorabji also appeals to additional sources, which
our sketch of his position can only survey in passing. For instance, he refers to ChrysippusÕ well-known example of the dog engaging in something analogous to theapplication of disjunctive syllogism (Sextus, PH 1. 69). Chrysippus explicitly states
CONTENT, CAUSE, AND STOIC IMPRESSIONS 11
Despite the considerable force and elegance of SorabjiÕs interpretation,we should have reservations about it as well. First of all, obviously muchdepends on an assumption that underlies his reading of the Stoics. He acceptsthe principle that we ought to ascribe intentionality to the impressions ofnon-rational animals if rational animals can articulate their content. In thisrespect, Sorabji acknowledges that he is following Dennett.36 Of course,one could have reasonable doubts about the success of DennettÕs instru-mentalism for the attribution of propositional attitudes.37 Yet, regardlessof whether we � nd DennettÕs position plausible, it has a certain lack of� t with Stoic theory. Dennett is an anti-realist about propositional atti-tudes.38 On his view, we ought to accept explanations of human behaviorthat employ beliefs and desires solely because of their usefulness. But,although this metaphysical issue will not be discussed fully here, it is clearthat the Stoics really admit desires and beliefs into their ontology. Theyare robust realists about propositional attitudes. Impulses and perception
that the mental activity of the dog is only in effect or passes for (dunamei ) reasoning.The Stoics deny that a dog can have beliefs, so it must grasp through perception thatone or more of the paths ahead of it does not have any scent. Sorabji also refers topassages from Hierocles, Seneca, and Chrysippus in which these authors discuss theearly stages of an animalÕs life. Self-awareness is necessary for self-preservation, animpulse which the Stoics claim all animal life possesses from the very start. The Stoicanalysis of self-awareness requires that animals are aware that they have particularbody parts, that their prey have weaknesses, and so forth. In ÒPerceptual Content inthe Stoics,Ó p. 312, he holds that such instances of self-awareness can only be under-stood by attributing propositional attitudes. In addition, he cites passages in Plutarchand Sextus (Plut. On the E at Delphi 386F-387A, Sextus M 8. 276) in which rationaland non-rational animals are distinguished in terms of whether they are capable ofinferential reasoning. Sorabji says that only rational animals can draw inferences.Although the Stoics are silent in these sources about the nature of animal perceptualimpressions, the texts suggest to Sorabji that the difference between rational and non-rational animals has little to do with whether or not their impressions have propo-sitional form. Consequently, these other sources also lead Sorabji to deny that non-rational animals are only capable of impressions completely devoid of propositionalcontents.
36 See Richard Sorabji, ÒPerceptual Content in the Stoics,Ó p. 314, ÒIntentionalityand Physiological Processes: AristotleÕs Theory of Sense-Perception,Ó p. 206, and Animal Minds and Human Morals, p. 28. He cites, in particular, D. Dennett, ÒCondi-tions of Personhood,Ó in A. Rorty, ed., The Identities of Persons (Berkeley: Universityof California Press), pp. 175-196.
37 E.g., see Jerry A. Fodor, ÒFodorÕs Guide to Mental Representation: The Intel-ligent AuntieÕs Vade-Mecum,Ó A Theory of Content and Other Essays (Cambridge,Massachusetts: The MIT Press, 1992), pp. 6-8.
38 See Jerry Fodor, ÒFodorÕs Guide to Mental Representation: The IntelligentAuntieÕs Vade-Mecum,Ó p. 7.
12 GLENN LESSES
are what distinguish animal life from other kinds of living things.39 Whenthey speak more precisely, the Stoics restrict desire (orexis), which theyde� ne as a kind of impulse that requires belief, to rational beings, thoughsome animal impulses can be relatively similar in nature to human desires.40 In any case, impulses, desires, and beliefs are identi� ed withmovements of the soul. Thus, the Stoics take such psychological states tobe instances of actually existing physical states.
Sorabji tells us very little about his predicational notion of proposi-tional contents. His position appears to come to this: there is a weak senseof ÒpropositionalÓ which means only that one thing is connected withanother.41 Animals have impressions that a is related to b. On his view,we should attribute propositional contents to the mental states of non-rational animals because their impressions contain the proposition that one thing is predicated of another. Sorabji commits himself to nothingmore than the position that propositions are what that-clauses introduce.As we already saw, the orthodox interpretation shares this core analysisof propositions. Sorabji also adds a distinction between perceiving-thatand perceiving-as.42 Accordingly, one might hold that animals can per-ceive, say, something as sweet even if one denies that they can perceivethat something is sweet. If we argue that the impression that gives rise tothe latter sort of perception corresponds to lekta, then non-rational ani-mals cannot entertain it. However, it is unclear what importance Sorabjiplaces on this distinction since he concedes that neither we nor the Stoicsneatly distinguish in this way between as and that.43
A more important problem is that SorabjiÕs attribution of propositionalcontents is far from restrictive. To say that non-animals perceive that a isrelated to b or that a is predicated of b is to attribute a huge class of whatthe Stoics must hold are impressions expressing lekta. If the Stoics denythat animals can entertain the impression that something is white, it ishard to see why they would attribute predicational mental contents to ani-mals or what real theoretical advantage follows. On what basis is it rea-
39 D.L. 7. 86. 40 Stobaeus 2. 86. 17 – 87. 6. For a discussion of Stoic distinctions among kinds
of impulses, see Brad Inwood, Ethics and Human Action in Early Stoicism, pp. 224-242. See also Julia Annas, Hellenistic Philosophy of Mind, pp. 89-102.
41 Richard Sorabji, ÒPerceptual Content in the Stoics,Ó p. 307, Animal Minds andHuman Morals, pp. 12, 17, 21.
42 See Richard Sorabji, ÒPerceptual Content in the Stoics,Ó p. 309, Animal Mindsand Human Morals, pp. 21-22.
43 Richard Sorabji, Animal Minds and Human Morals, p. 22.
CONTENT, CAUSE, AND STOIC IMPRESSIONS 13
sonable to accept that animals can have, for example, impressions that awhite thing is to the left of a blue thing, yet not attribute to them the im-pression that something is white? Frede and other proponents of ortho-doxy are right to deny that the Stoics would accept so generous a viewsince impressions with predicational contents also correspond to lekta andas such are accessible only to rational animals.
Finally, there are also textual reasons to be wary of SorabjiÕs reading.The sources to which he appeals often might reasonably be read moreweakly. In particular, I cannot � nd any passage that supports his positionthat the content of the impressions of non-rational animals can, in princi-ple, be articulated by rational animals. For instance, D.L. 7. 49, one pas-sage on which he places much importance, distinguishes between twomental operations: (i) the occasion of having an impression and (ii) for-mulating in words how one is affected through having it. The text is silentabout rational animals having the capacity to verbalize the impressions ofnon-rational ones. It is possible to read it simply as asserting that the agentin whom the impression occurs has the ability to express its content. More-over, some passages weigh against SorabjiÕs point. Consider part of Aetius4. 12. 1, which states of an impression: Ò[given through sight] we are ableto say (eipein ekhomen) that there exists something white which moves us(h¶mas); similarly for touch or smell.Ó44 In this passage, an impression islinked to what the agents themselves presented with an impression arecapable of verbalizing. Its contents can be expressed by the same subjectsin whom it occurs. Although such passages indeed show that the Stoicsdistinguish between what can potentially be expressed and what actuallyis verbalized, no mention is made of one personÕs impression being artic-ulable by another or of an animalÕs perceptual impression being verbaliz-able by us. A more natural and straightforward reading than SorabjiÕs isavailable to us. The Stoics do distinguish between what is articulable andwhat actually is articulated. However, this point applies only to rationalagents presented with an impression. Although rational agents normallycan express the content of some of their impressions, they do not alwaysactually articulate what these impressions convey. In other words, theStoics are sensitive to the difference between occurrent verbalization and
44 Aetius 4. 12. 1 is part of text (5) below. See Richard Sorabji, ÒPerceptual Contentin the Stoics,Ó p. 309, for his additional citations. Sextus M 7. 244 says of certainimpressions that it is possible to make a true or false assertion as a result (the true,persuasive ones, a true assertion, the false persuasive ones, a false one). Sextus M8. 70 similarly says of rational impressions that their content can be expressed inwords. See also Sextus M 8. 10, D.L. 7. 65, Sextus M 9. 211.
14 GLENN LESSES
an agentÕs ability to verbalize. Thus, it is consistent with the evidence thatthe Stoics are making a much more obvious point in these passages thanSorabji suggests.
III
The Stoics investigate the initial stages of animal development in termsof their doctrine of oikei¬sis. In the process that they describe, animalscome to have inclinations to act and become aware of themselves.45 Ani-mal life is distinguished from other kinds of living and non-living thingsin virtue of having impulses (hormai) and perception (aisth¶sis).46 For theStoics, perception is prior to impulse because animals must perceive them-selves in order for impulses to occur.47 Such impulses arise as a result ofimpressions with which animals are presented.48 Animals perceive them-selves (aisthanesthai heautou, Hierocles 1, 34-9, 51-7) continuously frombirth (Hierocles 1. 37-50, 3. 52-4. 53, 4. 53-4. 58). Chrysippus states thatan animalÕs initial inclination is based on Òthe � rst thing for every animalbelonging to it – its own constitution (sustasis) and the self-consciousness(suneid¶sis) of thisÓ (D.L. 7. 85).49 If self-perception is a species of per-ception, then self-perception also requires the occurrence of phantasiai .50
45 D.L. 7. 85, Cicero Fin. 3. 16. 46 See Hierocles 1. 30-37, especially, and D.L. 7. 86. HieroclesÕ arguments are dis-
cussed in Brad Inwood, ÒHierocles: Theory and Argument in the Second CenturyA.D.,Ó Oxford Studies in Ancient Philosophy 2 (1984), pp. 151-183, and in A.A. Long,ÒHierocles on oikei¬sis and self-perception,Ó Hellenistic Philosophy, vol. 1, ed. K.J.Boudouris (International Center for Greek Philosophy and Culture, Athens, 1994), pp. 93-104. LongÕs essay is a summary of more extended discussion in the edition of Hierocles that he together with Guido Bastianini have completed for the seriesCorpus dei Papiri Filoso ci Greci e Latini (CPF) I, vol. 1** (Florence, 1992).
47 See Cicero n. 3. 16, Seneca Ep. 121. Cicero actually refers to the desires ofinfants rather than their impulses. When the Stoics speak precisely, they typically dis-tinguish desire (orexis) from impulse (horm¶) and deny that non-rational animalsincluding human young can have desire, which is a species of impulse. Stobaeus 2. 86. 20 – 87. 6 indicates that orexis is a kind of rational impulse. See Brad Inwood,Ethics and Human Action in Early Stoicism, pp. 225-230, 235-237, A.A. Long andD.N. Sedley, The Hellenistic Philosophers, vol. II, p. 318, note on Stobaeus 2. 86. 17 – 87. 6, and Julia Annas, Hellenistic Philosophy of Mind, pp. 91-97.
48 See Stobaeus 2. 86. 20 – 87. 6, Origen, Prin. 3. 1. 2-3.49 He refers to self-consciousness in this passage, not self-perception. We have no
sources of which I am aware where Chrysippus speaks explicitly of self-perception. 50 One way to understand the continuous self-perception to which the Stoics refer
CONTENT, CAUSE, AND STOIC IMPRESSIONS 15
What is the nature of the initial impressions of self-perception? Answer-ing this question will help determine the extent of the Stoic attribution ofpropositional contents. Since these impressions occur from the moment ofbirth, the initial impressions cannot be the result of repeated experience.Stoic examples of self-perception often refer to speci� c animal body partsand functions. For instance, snails perceive their � esh and shells and birdsperceive their wings are for � ying.51 Self-perception sometimes is said toinvolve perceiving that something is the case but since such descriptionsare far from typical we should exercise caution about drawing too muchfrom this evidence.52 The Stoics often seem to be searching for a way ofspeaking that is less cognitively loaded and appear to be reluctant to at-tribute too much cognition to animals and human infants.53 In any event,these kinds of examples – such as the bull perceiving that its horns arefor self-defense – appeal to later stages of oikei¬sis. But self-perceptionalso occurs during the initial stages of oikei¬sis.
What about the original impressions that arise in self-perception in the
is that animals have a steady disposition to perceive themselves. It is also possiblethat they intend to make the stronger claim that animals are continuously perceivingthemselves occurrently. A.A. Long, ÒHierocles on oikei¬sis and self-perception,Ó pp.93-104, proposes an account along these lines of continuous self-perception in termsof proprioception, i.e., the notion of self-monitoring.
51 See Hierocles 1. 51-2. 3, Seneca Ep. 121. 18-20.52 See Hierocles 3. 2-6 and Seneca Ep. 121. 21. 53 For instance, Seneca, in a remark reminiscent of Chrysippus, says that every ani-
mal is aware of its constitution or physical makeup from birth (Ep. 121. 5-6). Theirawareness is the developmental basis for the other things that they perceive (Ep. 121.12). But he also thinks that it is a mistake to take animals or human young to be capa-ble of explaining their makeup or de� ning their constitution (Ep. 121. 11-13). Althoughnon-rational animals are aware of their ruling part, they cannot elucidate or expresswhat it is (Ep. 121. 13). Seneca makes an analogy (Ep. 121. 12) between the aware-ness that adult humans have of their souls and the awareness of non-rational animalsof their constitution. Though we perceive our souls, this awareness does not entail thatwe know the soulÕs nature or even its location. Similarly, when non-rational animalsperceive themselves, the impressions that occur do not include enough information to de� ne what they perceive or to say anything clearly about it. See also Seneca Ira1. 3. 7. Richard Sorabji, ÒPerceptual Content in the Stoics,Ó p. 312, is, of course, cor-rect that these texts and similar ones where the Stoics speak of the vagueness or lackof clarity of the perception of non-rational animals underdetermine whether their im-pressions are propositional. My point here is simply that Seneca marks non-rationalanimal perceptual impressions as somewhat weaker than the perceptual impressions ofrational animals. Though Seneca does not say exactly what is ruled out, he placesrestrictions on what the initial impressions of self-perception can contain.
16 GLENN LESSES
initial stages of oikei¬sis? In the following passage, the Stoics refer tobasic sense impressions:
(5) Chrysippus says that these four things differ from each other. Impression, then,is an experience ( pathos) which occurs in the soul and which, in [the pathos]itself, also indicates that which caused it. For example, when we observe some-thing white by means of vision, there is a pathos which has occurred in the soulby means of vision; and <in virtue of> this pathos we are able to say there existssomething white which stimulates us. And similarly for touch and smell. Impres-sion ( phantasia) gets its name from light ( ph¬s); for just as light reveals itselfand the other things which are encompassed in it, so too impression reveals itselfand that which caused it. The impressed thing is that which causes the impres-sion. For example, the impressed thing is the white and the cold and everythingwhich is able to stimulate the soul. [Aetius 4. 12. 1-3]
In conjunction with (5), consider also another similar text, which furtherhelps us to understand and explain differences in mental content:54
(6) And this pathos must be indicative both of itself and of the phenomenon whichproduced it, which pathos is not other than the impression. Hence, we say thatan impression is a pathos of an animal capable of presenting both itself and theother thing [i.e., its cause]. For example, Antiochus says, when we look at some-thing we are put into a certain condition with respect to sight and we do not haveour sight in the same condition as before we looked. In this sort of alteration,we take hold of (antilambanometha) two things, one, the alteration itself, whichis the impression, and, the second, that which produced the alteration, which isthe visible thing. And similarly in the case of the other senses. So, just as light( ph¬s) reveals both itself and everything in it, in this way the impression too,which is the beginning of the animalÕs cognitive functions, like light, must makeapparent both itself and the clear thing which is indicative of what produced it.[Sextus, M 7. 161-163]
Neither of these passages primarily concerns the kinds of examples of self-perception provided by Hierocles such as the bullÕs awareness of its ownhorns for self-defense. The accounts here are general descriptions of anyimpression of sense. In addition, text (6) speaks of the impressions as thesource of any cognition, which strongly suggests that these descriptionspertain to the earliest stages of oikei¬sis.
First, a preliminary question must be addressed. Do these passagesapply to both non-rational and rational animals?55 There is no reason to
54 The language of (6) is so similar to (5) that we should suppose that Antiochus isspeaking in his Stoicizing mode and that the passage genuinely re� ects Stoic doctrine.
55 This question is raised by Jean-Louis Labarri� re, ÒDe la Ônature phantastiqueÕ des
CONTENT, CAUSE, AND STOIC IMPRESSIONS 17
think that these texts are restricted to a discussion of the beginnings ofcognition in rational animals. (5) speaks generally of the notion of impres-sion and gives an account of its etymology. If these sources mean toinclude the impressions of human newborns, then they are likely also torefer to the impressions of any non-rational animal. Furthermore, text (6)refers very broadly to the impressions of an animal (to z¬on). Even moresigni� cant is that in (6) we discover that impressions are related to theÒbeginnings of an animalÕs cognitive functions.Ó Thus, we should con-clude that our sources here describe theoretical features shared by impres-sions generally.
An examination of these general features produces a relatively circum-scribed notion of propositional contents. First of all, we are told thatimpressions of this sort reveal their causes. The Stoics do not say that animpression has features which copy the characteristics of its cause. As anexample, sight is said to perceive the white, which is identi� ed as thecause of the impression. There is no indication that the perception of thewhite includes the impression that something is white. According to (5),the white, the cause of the impression, is the impressed thing (phantaston)and is indicated in the impression itself. Recall that in text (4) Cicero dis-tinguishes between what the senses perceive – whiteness – and what isactually perceived by the mind, not the senses – the proposition that some-thing is white. There are puzzles about this passage to which we willreturn shortly, but for the moment at least it is reasonable to suggest thatthe sense-impression has the impressed thing, viz., the white, as part of itscontents but does not have the proposition that something is white as part.Passages (5) and (6) also stipulate that a sensory impression is capable ofconveying some additional content for we are told that the sense impres-sion reveals itself. Thus, provisionally we can say that sense impressionof white includes the following contents: (i) the white, which indicates the cause of the impression, and (ii) the occurrent impression (i.e., of thewhite) itself. At this point, we do not have to commit ourselves to speci-fying that these mental contents are propositional in form. But it is clearthat the proposition that something is white goes beyond the ascription ofthese modest contents.
According to (5), the impression of white is then the basis of our say-ing that Òthere exists something white.Ó The Stoics are cautious here about
animaux chez les Sto�ciens,Ó pp. 238-243, though in the context of whether animalshave any self-consciousness. As a result, he never directly poses the question aboutthe cases of self-perception on which we focus.
18 GLENN LESSES
the source of that propositional information. Is the proposition that some-thing white exists already contained in the impression? If it is, then it istempting to conclude that non-rational minds are incapable of discerningall the contents already contained in the impression. But an alternativereading is also possible. It must be conceded that the evidence underde-termines either interpretation, however, the second reading is preferablefor the sake of consistency with our earlier analysis of (5) and (6). Thesesources are fairly speci� c about what narrow contents are contained gen-erally in impressions. In addition, (4) tells us that rational animals bringother mental operations into play which affect their impressions. On thepreferred reading, a rational mind contributes some new information,which expresses the proposition that something is white, to the contentsof the original sense-impression.56 A propositional mental state of this sortmight well be broadly described as inferential. A rational animal is capa-ble of inferring that, e.g., if a white thing causes my impression, then itis the case that something is white. For the Stoics, any inference about thecause of the impression of whiteness requires an ability of which non-rational minds are incapable. Even in the well-known Chrysippean exam-ple, the dog employing disjunctive syllogism is only said to simulate reasoning.57 One might plausibly hold that inferential reasoning, how-ever minimal and automatic the inference, requires other operations of themind besides perception.
Let us return to text (4), which makes some distinction about content.58
The senses are said to perceive things such as whiteness. Yet, Cicero holdsthat the senses perceive only in a way propositional claims such as thatsomething is white. It is not altogether obvious how to unpack this pas-sage.59 If we read Cicero rather literally here, he distinguishes between
56 Julia Annas, Hellenistic Philosophy of Mind, pp. 82-84, discusses a parallel setof interpretations for kataleptic vs. non-kataleptic impressions in rational animals.
57 Sextus, PH 1. 69 states that the dog in effect (dunamei) is reasoning. RichardSorabji, ÒPerceptual Content in the Stoics,Ó p. 313, takes this instance of simulatedreasoning to be more or less a legitimate case of reasoning.
58 I am making a weaker point here than Frede, who argues that text (4) rules outthe possibility of non-rational impressions having content at all.
59 We saw that the passage, according to Sorabji, ÒPerceptual Content in the Stoics,Óp. 311, commits the Stoics to impressions having propositional form. He proposes that if the senses can perceive in a way that something is the case then in a waysuch impressions can have propositional form. He states that to be Òpropositional ina wayÓ when the senses perceive that, say, this is white can be understood as thesenses Òpresent a non-verbalized appearance as of somethingÕs being white.Ó
CONTENT, CAUSE, AND STOIC IMPRESSIONS 19
what the senses can perceive only in a way and what the mind – here,referring to mental operations in the h¶gemonikon other than sense-perception – perceives fully. Perception involves assent so that in eachinstance the mind assents to what is presented. On the orthodox view,there is simply less to assent to in the case of what is presented only tothe senses. There also appears to be a reading consistent with SorabjiÕsinterpretation if what the mind contributes is an articulation of the con-tent that is already present in the original impression of sense. Let me suggest a third possibility. If animal minds are incapable of making infer-ences from what they do in fact perceive, then CiceroÕs remarks that themind alone secures that, say, this is white applies only to rational animals.The senses of rational animals alone can grasp in a way that somethingis white because they alone can draw inferences based on their sensa-tions. FredeÕs orthodox interpretation is mistaken in supposing that (4)supports the view that animals perceives only qualities. SorabjiÕs alterna-tive is also incorrect because non-rational impressions are not the issuehere. The context of Acad. 2. 21 shows that the impressions being con-sidered are only those of rational animals. So CiceroÕs discussion appliesonly to impressions of rational animals and has little to do with impres-sions of sense generally.60
In texts (5) and (6), we saw that the impressions of sense are said toreveal their causes. In the case of an impression of whiteness, the causeof the impression is the white, which is the impressed thing (phantaston).The passages speak of Òthe whiteÓ (to leukon) or Òthe visibleÓ (to horaton),which could refer, of course, either to the quality of an object or to anobject itself. But we do not need to commit ourselves to either alterna-tive and so will speak just of qualities in what follows. Additionally, theclaim that the impressionÕs cause, the white, is revealed might be takenin two ways. First, one might hold that the impression reveals some-thing, which, as it happens, caused it. In the case of the impression of awhite thing, what gets revealed is just whiteness. If all the Stoics mean isthat the perceiver sees whiteness, then nothing more is contained in theimpression than the rudimentary perception of a quality, whiteness. Thisreading of the texts is consistent with the orthodox interpretation. But,according to a second possible interpretation, what gets revealed when animpression reveals its cause is considerably more content-laden. The whiteis revealed as the cause of the impression. So, when these passages say
60 I am grateful to John Ellis for clarifying my point on Acad. 2. 21.
20 GLENN LESSES
that a sensory impression reveals its cause, they mean that, generally, aquality is revealed as the impressionÕs cause. On this reading, the subjectcan have an experience of causal relations.
The second interpretation is preferable. Why? The language and con-text of these passages supports this alternative for two reasons. First, theuse of the term ÒrevealsÓ must be consistent throughout the passages.Hence, we should apply how ÒrevealsÓ is employed when an impressionis said to reveal its own occurrence to the case of an impressionÕs cause.In texts (5) and (6), the Stoics describe impressions so that even non-rational animals perceive that an impression belongs to them. The pointis that the subject – rational or non-rational – is aware of its impression.If, as seems likely, this awareness requires some propositional attribution,then it is also likely that an impression reveals more than the rudimentaryawareness of a quality when the impression reveals its cause. Second, text(6) speaks explicitly of the subject also having the capacity to be awareof or grasp Òthe clear thing which is indicative of what produced itÓ(heaut¶n te emphanizein opheilei kai tou poi¶santos aut¶n enargousendeiktik¶ kathestanai).61 This description of what an impression revealsabout its cause entails that more is revealed than just some quality, which,as it happens, causes the impression. The content of the impression clearlypoints to what produced it. In other words, something is revealed as thecause of the impression. The content of such an impression explicitly con-tains causal relations of which a perceiver can be aware.
In an interesting way, this reading of the content of an impression canalso be linked to Stoic remarks about self-perception and oikei¬sis. Thecontents of an impression make possible, in part, the awareness that the impression is occurring because the impressionÕs occurrence is itselfconveyed in its contents. If an impression reveals itself in this way, we can formulate a kind of self-perception that has been unnoticed by com-mentators.62 A perceiving subject can be aware of its own basic mentalstate – the impression itself. It is possible to analyze the initial instancesof self-perception to which oikei¬sis refers in terms of such awareness.
61 My rendering closely follows Brad Inwood and L.P. Gerson, Hellenistic Philos-ophy, here. A.A. Long and D.N. Sedley, The Hellenistic Philosophers, vol. 1, trans-lates the passage Ò[the impression] must be capable of revealing the self-evident objectthat caused it,Ó which even more strongly suggests that more than just a quality isrevealed. A self-evident feature is that the quality or object is related to the impres-sion as its cause.
62 Nothing in this discussion is meant to suggest that such impressions are kataleptic.
CONTENT, CAUSE, AND STOIC IMPRESSIONS 21
Very generally, oikei¬sis describes a process of something coming to be-long. If applied to individuals, the process refers to that which comes toÒbelong to meÓ or is Òof mine.Ó63 The account of mental contents we havedescribed thus � ts well with oikei¬sis. The Stoics hold that in the earlystages of oikei¬sis impressions occur because all animals from birth oncome equipped with impulses and the basis of their initial impulses is self-perception. These impressions include as part of their contents that theimpression itself belongs to the perceiver. In this minimal sense of self-perception, the Stoics attribute suf� cient cognitive functioning to non-rational animals so as to discriminate between their own psychologicalstates and whatever is alien64 to them. The contents of the impressionsthemselves indicate that they are the perceiverÕs and not of somethingindependent. 65
An example might help to illustrate the basic features of mental con-tent that have emerged in our discussion. Suppose that Dion has a dog,Zeno. What are the contents of ZenoÕs sensory impressions? If Zeno seeshis paw, he has an impression which, � rst of all, he is aware of as his.In addition, various causal relations constitute part of the contents of hisimpression. ZenoÕs impression contains at least something like the fol-lowing: his impression is caused by his paw. Thus, it can be said of Zenothat he perceives his paw. What cannot be attributed to Zeno is that heperceives that it is a paw. The Stoics also deny that Zeno draws infer-ences from what he perceives or that he can assess the truth of the con-tents of his impressions. The basic point is that the Stoics are makingsome sort of distinction between perceiving and perceiving that. Theywant to explain why Zeno perceives his paw but doesnÕt perceive that it is a paw. They construct their explanation in terms of a somewhat restricted set of propositional contents.
63 See S.G. Pembroke, ÒOikei¬sis,Ó Problems in Stoicism (London: Athlone Press,1971), ed. A.A. Long, pp. 115-116, Julia Annas, The Morality of Happiness (Oxford:Oxford University Press, 1993), 262-263. ÒOikei¬sis,Ó the verbal noun which becomesStoic technical usage, is related to the adjective Òoikeios.Ó This latter term originallymeant Òof the householdÓ and picks out members of a household, their relations, andothers connected to it less immediately. The term applies also to property and, deriv-atively, comes to have the sense of Òanything belonging to a person.Ó
64 I.e., allotrion, the opposite of oikeion.65 In addition, we can conjecture that awareness of this feature of mental content
can constitute a kind of assent to the impression. If we could establish this case, thetwo-stage model of perception – having an impression and assent to it – still can � tthe account of impressions with modest contents.
22 GLENN LESSES
Of course, even if this interpretation is correct, the Stoic position mightturn out to be muddled. For one thing, it might plausibly be held that anawareness of causal relations requires concepts. Yet, the Stoics deny thatnon-rational animals are capable of conceptual thought. In addition, thereis the fundamental problem that non-rational impressions cannot expresslekta. But in the interpretation that we have developed, non-rational ani-mals perceive causal relations: that one thing causes something else. It is unlikely that the Stoics can make these kinds of propositional con-tent consistent with their of� cial position about lekta. Perhaps the con-tent of such impressions is restrictive enough that they did not notice theproblem.66
In any case, the Stoic account of the initial stages of animal develop-ment also supports a conception of mental contents that is narrow andrestrictive. In this sense, the content of an impression has only to be ade-quately rich (i) to represent certain causal relations and (ii) to signal thatthe impression itself is occurring in the perceiver. The Stoics can try toexplain the ability of non-rational animals to function cognitively in termsof their power to entertain such impressions. The Stoics are also adamantthat non-rational animals are incapable of belief.67 Thus, the nature ofimpressions in rational and non-rational animals is readily distinguished.By formulating an account of a more restricted mental content, the Stoicscan explain the observed, cognitive behavior of non-rational animals andalso differentiate between non-rational and rational animals.
In this essay, I have tried to show that there is interpretive spacebetween the austerity of FredeÕs orthodox view and the too charitablealternative presented by Sorabji. Frede is mistaken that all non-rationalimpressions are devoid of propositional content. Not only do animals per-ceive whiteness, sweetness, and other qualities, they also can be aware ofcausal relations. On the other hand, Sorabji is wrong to attribute relatively
66 These problems could have led the Stoics to offer a more familiar theory of causalcontents in which the meaning of the impression is simply whatever causes the impres-sion. This kind of content does not require attributing any propositional content at allto non-rational animals. Such a position would then be consistent with the orthodoxview. But there is little evidence that they do, in fact, propose a version of this sortof causal theory of content.
67 On the Stoic view, it is clear that rational animals have impressions that are robustly propositional in form. Roughly, beliefs involves assent to an impression which contains what are termed ÒsayablesÓ (lekta). Sayables are rather similar to state-ments. Earlier, we saw that impressions containing sayables are equivalent to thoughtsand occur only in rational beings.
CONTENT, CAUSE, AND STOIC IMPRESSIONS 23
unrestricted propositional content to non-rational animals.68 Both accountsfail to notice another sort of propositional contents, which the Stoics caneffectively employ in their systematic and careful inquiry into philosophyof mind.69 Thus, the Stoics hold a position that is intermediate betweenthe two interpretations. The more narrow propositional contents of impres-sions include a type of self-perception of mental states and an awarenessof causal relations. The application of this more restrictive notion enablesthe Stoics within the context of their overall naturalism to develop a
68 Sorabji evidently tries to formulate something weaker than full-� edged proposi-tional content when he employs his conception of predicational content. Though henever completely explains his notion, it enables him to distinguish between predica-tional content and the stronger type of content involved in assenting to a belief. How-ever, he at least must clarify why saying of an animalÕs impression that, for instance,the scent is in a certain direction commits him to so much less in terms of proposi-tional contents than the position that there is an impression that something is white.There obviously are complex issues of reference and opacity to be dealt with in bothcases, which we will put aside.
See A.A. Long and D.N. Sedley, The Hellenistic Philosophers, vol. 1, p. 240, forone attempt to explain a position that at � rst appears similar to SorabjiÕs. They dis-cuss this sort of impression in terms of an example. Imagine seeing a John Waynemovie in which Òwe get the impression of John WayneÕs being on the screen in frontof us, but not of course the impression that John Wayne is on the screen in front ofus (p. 240).Ó Their point is really to distinguish a person having beliefs from merelyhaving impressions. For Long and Sedley, only the second is a case of belief. How-ever, they do not explicitly deny the � rst case also has propositional content. Theirexample shows we must exercise caution about specifying the propositions containedin an impression, not that there is none. One might argue that the � rst case alsoinvolves beliefs, though there are issues about what is believed. Long and Sedley denythat non-rational animals can have concepts and agree with the orthodox view thatnon-rational impressions are empty of mental content. But this illustration concernsquestions about a personÕs impression of WayneÕs being on the screen. Hence, issuesabout whether their account commits us to denying the ascription of impressions withpropositional form to non-rational animals never really arise.
69 The project undertaken in this essay is limited to constructing an interpretationthat is intermediate between the two standard ones. There are a number of open ques-tions. Perhaps the most important is how the two-stage model of perception applies toimpressions having only modest mental contents. The nature of assent in the case ofnarrow content must be distinguished from that of robustly propositional impressions.How exactly does the mind assent in the former case? There are related questionsabout the nature of impulses since perception is the basis of impulse. Any impulsesto which non-rational impressions give rise must be different in kind from the impulsesgenerated by rational impressions. Ultimately, these issues can affect Stoic moraltheory because the Stoics tie their account of moral development to the nature ofimpulse.
24 GLENN LESSES
remarkably uni� ed and subtle theory of mental content. The distinctionsthat they make about types of content yield an account of the continuityand contrast between non-rational and rational minds.70
College of CharlestonCharleston, South Carolina
70 My initial work on these issues began while I was a visiting scholar at HarvardUniversity, where I was generously allowed the use of its resources. I have delivereddifferent parts of early versions of this essay to a number of audiences to whom I amgrateful, especially, to those present at the American Philosophical Association meet-ing in Chicago in April 1995. I have bene� ted from suggestions and criticisms on allthese occasions, and, in particular, from the subsequent written comments of ShaunNichols and Joyce Carpenter. I owe a special debt to John Ellis, the respondent at theAPA meeting, whose stimulating discussion and written remarks greatly improved thisessay.
