Monthly Archives: July 2012

What is the Function of the Kataleptic Impression & does it Stand Against its Critics?

The Stoics, led by Zeno of Citium, proposed an epistemological view which held that knowledge comes from a harmonious unity of kataleptic phantasia of the external world which is perceived through our sensory apparatus. Once we have obtained knowledge n this way we may master our emotions and become indifferent to the external world, making us free from the troubles and strife people normally run into because of their opinions about the external world. This is, for the Stoics at least, the good life at which we should all aim for. However the Stoics’ views have come under a series of criticisms from a rival school known as the Academics, led by Arcesilaus, who were best known for their sceptical views. Although as hard as the Academics tried to disprove the Stoics the Stoic viewpoint managed to withstand all of its criticisms and has even managed to withstand some of the criticisms made against it by modern sceptical approaches such as Cartesian scepticism.

The Stoics are the group of philosophers who follow the teachings of Zeno of Citium who after being shipwrecked, during a voyage to deliver dye, met Crates through a chance encounter in a bookshop (if the stories are to believed) who he spent studying under for some time before putting forward “his arguments while walking back and forth in the Painted Stoa”[1]. It was this reason that his followers became known as the Stoics, although they have also been referred to by some as the Zenonists; however to save confusion throughout this essay their more renowned title of Stoics shall be used. For the Stoics philosophy is a tripartite theory covering logos, ethos and phusikoi (logic, ethics and physics respectively). The concept of kataleptic impressions falls under Stoic logos as it plays a part in their epistemological theory. But what exactly is a kataleptic impression? Before we can gain any further understanding of Stoic epistemology this question must be answered, but first an explanation of Stoic epistemology shall be given.

The Stoics believe that the starting point for knowledge is sense-data, which appears to us as presentations. Before we begin to obtain presentations of the external world “the human mind is like a blank sheet of paper”[2], so for the Stoics all knowledge is a posteriori, there is no allowance for innate a priori knowledge, and from this it is possible to argue that the Stoics were an early form of empiricists. Once sense-data “arises from that which is; is stamped and impressed in accordance with that very thing”[3], in other words when a presentation has entered through our senses it stamps itself firmly upon the mind to create an impression, or phantasia. According to Sellers the phantasia is a key point for knowledge within Stoic epistemology as “the point of departure for Stoic epistemology is the impression”[4], it is from this departure we can now move onto what is meant by a kataleptic impression.

Now it has been established that “a presentation is an impression in a soul”[5] we can move onto the next phase of obtaining knowledge as “knowledge itself, they say, is either a secure grasp or a disposition in the reception of presentations”[6], or in other words knowledge is the grasping of impressions derived from the various presentations of the external world we perceive via our senses.  In order for us to be able to grasp something we must show our assent, otherwise if we withhold our assent then we cannot fully accept it as knowledge as the disagreement we have allows room for doubt. “The Stoics characterize true impression to which we should assent as “adequate” or “cognitive” (katalēptikē) impressions…literally a grasping impression”[7]. Hence a kataleptic impression, or a kataleptic phantasia, is an adequate impression which we should assent to as being adequate its truth is self-evident. Thus a kataleptic phantasia can be defined as being a grasping impression since to grasp something we must show our assent to it, and we should assent to impressions which are adequate as these are the ones which have self-evidential truth contained within them. So now we have a definition for what a kataleptic phantasia is what function does it play within Stoic epistemology?

Kataleptic phantasia have the role of guiding us towards truth, according to Stoic epistemology, as these and only these impressions are adequate enough to stop our reason from going astray. “The cognitive impression was supposed to fill that role: when you experience one of these, provided that you recognise it as such you can…assert definitely that the matter in question is true”[8]. Thus it is the role of kataleptic phantasia to direct our experience of the external world towards truth, but only as long as we can recognise that the phantasia is adequate enough to do so otherwise we should abstain with offering our assent. Should we be unable to recognise which phantasia are kataleptic phantasia then we will be like “those who are not well exercised in handling presentations”[9] and “turn to unruliness”[10], by which it is not meant that we shall become unruly in behaviour, instead it is meant that we shall become unruly in mind. If we allow ourselves to become unruly of mind then we shall never grasp knowledge for our cognition will be full of fantasy, opinion and all manner of falsehoods blinding us from the true nature of things. A view which echoes back to Plato who in The Republic warned that if we do not try to grasp the Forms then we shall remain blind from the truth and be unruly like a wild beast. Thus it is not just the role of kataleptic phantasia to guide us to truth but to also save us from falsehood, although it could be argued that by doing one the other is implemented simultaneously.

However it is not enough for kataleptic phantasia to simply guide us to truth, and therefore knowledge, there must be something important about knowledge that makes it so vital that we must obtain it. “Real knowledge (episteme) requires cognition which is secure, firm and unchangeable by reason…worked into a systematic whole with other such cognition”[11]. So knowledge is not built upon a single kataleptic phantasia but a multitude of them arranged into a harmonious unity, so knowledge is not held within kataleptic phantasia but in the synthesis of them. And for the Stoic once we have built such a unity then we will become indifferent to our presentations of the external world, being able to disengage from emotion, and therefore capable of reaching a state of tranquillity so that we may live ‘the good life’. This is the true aim for the Stoic, “to live in a state of indifference”[12]. Therefore the ultimate purpose of kataleptic phantasia is to help us arrive at indifference so that we may take part in ‘the good life’.

However Stoic epistemology is not without its critics with the Academics being at the forefront of criticism put against the Stoics. But just who are the Academics? The Academics are those who studied in the Academy after Arcesilaus took over as its head and turned the Academy from a school of Platonism into a school of scepticism, and so “the first of the Academic skeptics is Arcesilaus…who served as Head of the Academy”[13]. Arcesilaus taught that “skepticism aims at happiness”[14] as opposed to the Stoic belief that happiness comes from indifference. For the Academics we can never hold any truth as there we can also doubt the roots of what we perceive to be truth, for example the Stoics took sense-data to be the ultimate root yet the Academics say we can doubt that our senses will function properly so such sense-data can be fallible. Although Arcesilaus did hold some respect for the Stoics as he “agrees with Zeno [the Stoic] and holds that the wise man’s chief strength is that he is careful not to be tricked and sees it that he is not deceived”[15].

One of the criticisms posed by the Academics comes from a general confusion between objects that appear identical but are actually very similar, which urged the Academics to ask “could a true presentation be of the same quality as a false one?”[16] For example if we were given a shiny red apple and a shiny red wax apple, then to our senses we have been presented with two shiny red apples. Yet in reality we only have one shiny red apple, so form this perspective it is possible to have a false presentation which is just as forceful as a true presentation making it unclear as to which we should assent to and take as a kataleptic phantasia. This point was later picked up by one of Arcesilaus’ successors, Carneades who said “there can be no criterion which establishes certain truth because reason…and any other possible criterion sometimes mislead us”[17] and later on this point was brought back up in Cartesian scepticism as Descartes stated “everything I have accepted up to now as being absolutely true…I have learned from…the senses. But I have sometimes found that these senses played me false, and it is prudent never to trust entirely those who have once deceived us”[18]. So if Stoic epistemology relies heavily on the senses but the senses are not ideal tools for seeking truth, then it would seem that the Stoics have placed their trust incorrectly.

However the Stoics respond to this by saying that “an adequate impression is an impression…so clear, vivid and distinct that it is its own guarantee of…accuracy”[19]. Therefore kataleptic phantasia would be so self-evidently true that we shall never fall for such a confusion of the sense so long as are adequately trained in identifying kataleptic phantasia. Once we have managed to train ourselves in such a way then we become Sages, or wise men, grasping nothing but knowledge and truth.

A further criticism put forward by the Academics is “if a wise man ever assents to anything, then he will sometimes hold [mere] opinions”[20] due to the fact that all we can ever perceive is our own subjective view of the external world around us, as Carneades pointed out “the impressions…that inform our judgements are not completely objective”[21]. This being the case then the Stoic Sage with his (or her) harmonious unity of kataleptic phantasia has still managed to grasp nothing better than, at best, opinion with accidental truths scattered about within. This criticism then goes a stage further it the Academics ask “what would happen if…the wise man could not perceive anything?”[22] Surely if the Sage could not perceive anything then he would be unable to hold any kataleptic phantasia to construct a harmonious unity, therefore be unable to have any grasp of knowledge or truth.

The Stoic response to this is the Sage would abstain from asserting to the phantasia or to any claim made by another on his (or her) behalf as the Sage would not wish to bother themselves with mere opinion, and so would reject it even if that leaves them in a position where they then hold nothing at all. For even if they hold nothing at all they can still remain indifferent to the troubles faced by others and therefore partake in ‘the good life’. For example if a Stoic Sage holding neither knowledge nor opinion were on a boat amongst others and a wave was about to crash down upon them, then the others would panic as their opinions of the event would tell them that the wave would be of harm to them, yet the Stoic, who is without these opinions, will remain calm and contented.

Although the Academics are not completely satisfied by this argument as even the wisest Stoic still expressing such emotions giving the circumstances explained above. So the Stoics explain that in these rare occurrences the phantasia are so strong that they are thrown upon us by force robbing us of our assent before we have chance to rationalise the siltation, or as Sellers puts it “the impressions we receive that present external objects…are not within our control…they force themselves upon us”[23]. Once we have managed to fight back against the immediate strength of the phantasia are rationalise things we are then able to take back our assent and once more be indifferent to the situation at hand.

A final criticism made by the Academics concerns the claims made by mad-men and those whose senses have gone astray. A criticism Descartes later uses in his first meditation where he asks about those “insane persons whose minds are…clouded by the black vapours…that they constantly assert that they are kings”[24]. The Stoic response to this is that madness does not accurately reflect the cognition of normal human beings, hence this line of attack is not a particular good one. It is not good logic to make claims about things which in some resemble the thing you wish to attack but is not actually the thing you wish to attack. Frede also offers help to the Stoics by saying that “if one’s sense organs, the object in question, and all other variables are not…in an abnormal state, then the resulting impression will be an adequate impression”[25]. Which means that provided we do not suffer from a madness, partake in narcotic influences, suffer from myopia or some other complication of the senses, then it should follow that we safely derive kataleptic phantasia from the sense-data we perceive from the external world.

To conclude a kataleptic phantasia, or grasping impression, is a self-evidential truth of nature to which we have assented to. It plays a key component of Stoic epistemology as it is from these kataleptic phantasia we build a harmonious unity which we derive true knowledge from so that we become capable of being indifferent to the external world allowing us to engage with ‘the good life’. Yet the Academics have attempted to criticise this epistemological theory by putting forward arguments concerning false impressions, faulty senses and the subjective nature of human reasoning, all of which have been responded to by the Stoics with plausible explanations. Not only has the Stoic managed to fend off the arguments of the Academic sceptics but has also managed to deal with arguments put forward by modern sceptics such as Descartes. Therefore it would seem that Stoic epistemology is a sturdy theory.


  • Descartes. R, (1968), Discourse on Method and The Meditations, London: Penguin Classics
  • Frede. M, (1983), “Stoic Epistemology”, in The Skeptical Tradition, Burnyeat. M, 65-93, Berkeley: University of California Press
  • Inwood. B and Gerson. L, (1997), Hellenistic Philosophy Introductory Readings (2nd Edition), Indianapolis: Hackett
  • Plato, (2007), The Republic (2nd Edition Reissued), London: Penguin Classics
  • Sellers. J, (2006), Stoicism, Chesham (Buckinghamshire): Acumen
  • [accessed at 10:07 21st November 2009]
  • [accessed at 9:48 21st November 2009]

[1] Inwood. B and Gerson. L, Hellenistic Philosophy Introductory Readings (2nd Edition), 1997, Pg. 104

[2] Sellers. J, Stoicism, 2006, Pg. 65

[4] Sellers. J, Stoicism, 2006, Pg. 65

[5] Inwood. B and Gerson. L, Hellenistic Philosophy Introductory Readings (2nd Edition), 1997, Pg. 112

[6] Inwood. B and Gerson. L, Hellenistic Philosophy Introductory Readings (2nd Edition), 1997, Pg. 112

[7] Sellers. J, Stoicism, 2006, Pg. 68

[9] Inwood. B and Gerson. L, Hellenistic Philosophy Introductory Readings (2nd Edition), 1997, Pg. 112

[10] Inwood. B and Gerson. L, Hellenistic Philosophy Introductory Readings (2nd Edition), 1997, Pg.112

[12] Inwood. B and Gerson. L, Hellenistic Philosophy Introductory Readings (2nd Edition), 1997, Pg. 106

[15] Inwood. B and Gerson. L, Hellenistic Philosophy Introductory Readings (2nd Edition), 1997, Pg.269

[16] Inwood. B and Gerson. L, Hellenistic Philosophy Introductory Readings (2nd Edition), 1997, Pg. 270

[18] Descartes. R, Discourse on Method and The Meditations, 1968, Pg. 96

[19] Sellers. J, Stoicism, 2006, Pg. 69

[20] Inwood. B and Gerson. L, Hellenistic Philosophy Introductory Readings (2nd Edition), 1997, Pg.269

[22] Inwood. B and Gerson. L, Hellenistic Philosophy Introductory Readings (2nd Edition), 1997, Pg.269

[23] Sellers. J, Stoicism, 2006, Pg. 66

[24] Descartes. R, Discourse on Method and The Meditations, 1968, Pg. 96

[25] Frede. M, “Stoic Epistemology”, 1983, Pg 71-72

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