Ton Deuteron Ploun

Hellenistic philosophy is dominated by the Stoic/Skeptic debate with both sides considering themselves followers of Socrates.

The Stoics hold that knowledge is very difficult to attain and yet it is attainable. Because knowledge is attainable, nature must provide us with the means to acquire knowledge. It does this by providing us with clear and distinct impressions. Stoic epistemology is based on the doctrine of clear and distinct impressions and so the skeptics focused their debate on that aspect of their epistemology.

The Stoic Position

Impressions

Both humans and animals have impressions, though the impressions of humans (qua rational) are rational impressions.

Rational impressions (RI) have propositional content (we should interpret this notion of ‘impression’ in the way that we would interpret it in the statement ‘the impression which one gets, if one looks at the evidence, is that…’)

RI’s present themselves to the mind and the mind either accepts them or refuses to accept them.
* to accept them is to have the belief that the proposition is true
* to refuse to accept them is to suspend judgment regarding the veracity of the proposition

The Stoics held that the σοφος will never have any false beliefs. This is possible because humans are able to distinguish mere impressions from καταληψεις without fail.
* These καταληψεις provide an ample foundation for what we need to know
* By only accepting καταληψεις we may not accept many true impressions, but we will never accept a false impression.

This account presupposes two things:
1) there are καταληψεις
2) the mind can distinguish between καταληψεις and other impressions
To understand how the Stoics can make these assumptions, we must look at the Stoic account of rational impressions.

All RI’s, even the most primitive, involve concepts and cognitions. Part of what an object does is make the mind conceptualize it in a particular way.

“RI’s and in particular cognitive impressions do presuppose concepts, but these arise from more primitive impressions that do not presuppose these concepts, and ultimately from sense impressions that do not presuppose any concepts whatsoever but that are not rational either” (154).

So we have a non-ad hoc account of the development to RI’s.

There is more to an RI than the propositional content. To have an RI is to think of a certain proposition in a certain way. The kind of impression that it is depends on 1) the propositional content and 2) how the propositional content is thought.

Impressions:
* are impressions of an object
* consist of a thought concerning the object
* the thought involves a conceptualization of the object
* this thought need not be entirely conceptual
* the thought is characterized by the proposition AND the way the proposition is thought
* the way the proposition is thought depends on the way the constituents of the thought are represented in the thought

Cognitive Impressions (καταληψεις)

Impressions have a causal history and in the course of this history all sorts of things can go wrong. HOWEVER, we can imagine that nature has made it such that under normal conditions the impression we receive is true. So impressions with the right causal history are guaranteed (presumably by nature) to be true. We can call these normal impressions.

There are at least two kinds of normal impressions:
1) when the NI is not produced or caused by the object of the impression itself. I might have the NI that 2+2=4 because I have a proof that 2+2=4.
2) When the NI is produced by the object of the impression. This only happens in the case of perception. Looking at an apple gives me the impression of an apple; this impression is caused by the object of the impression. We can call these perceptual impressions.

At SE 7.424 we are given five conditions which must be met for a visual impression to be cognitive:
1) conditions on the sense organ
2) conditions on the object of vision
3) conditions on how the object is placed
4) conditions on how the impression comes about
5) conditions on the state of mind of the perceiver

The Stoics appear to think that cognitive impressions are perceptual. There’s a worry with this idea, though.
* They also clearly assume that there are non-perceptual cognitions (in cases where we have a proof of a theorem, for example).
* But even non-perceptual cognitions involve impressions.
* So it seems natural to assume that the impressions involved in cognitions are cognitive, even if they’re non-perceptual.
* But if there are non-perceptual cognitions, then there should be non-perceptual cognitive impressions.
* Besides, cognitive impressions are supposed to be a criteria of truth such that they guarantee the truth of all other impressions that the σοφος accepts. If we restrict cognitive impressions to those garnered from perception, it is hard to see how this could act as a sufficient foundation for the σοφος.

How can we respond to this worry?
First, we can see that the Stoics hold that all features of objects are perceptible. We can learn to see that something is good just like we can learn to see that something is a man. Perception, then, provides a much broader basis than we would initially assume.

Also, all other impressions can be accepted as true to the extent that their truth is guaranteed by the truth of perceptual impressions.
“It seems that the Stoics take on the view that only perceptual impressions are cognitive in their own right. Thus other impressions can be called cognitive only to the extent that they have a cognitive content which depends on the cognitive content of impressions which are cognitive in their own right” (159).

SO, there are two types of impressions:
1) self-evident impressions that are cognitive in a narrow sense (perceptual impressions (?))
2) evident impressions that are cognitive in a wider sense. (impressions that depend on perceptual impressions (?))

Perceptual impressions represent the objects the way they do because the objects are that way. The represented features of the impression are due to the object and not some abnormal condition.

So a perceptual impression in no way misrepresents its objects, under normal conditions. We can tell clearly what its visual features are; these impressions are evident.

Evidence is an objective feature of impressions in much the same way that having a clear view of something is an objective fact, not a subjective feeling.

Impressions are true because their propositional content is true; it doesn’t depend on the way the propositional content is thought.

Evidence is a feature of impressions which does depend on the way a proposition is represented by thought. The proposition “this is blue” can be evident when thought because I see the blue ink while non-evident when I hear from someone else that the ink is blue.

“What makes a thought or impression evident is that it is already part of the representation of the subject of the proposition that the predicate should be true of it and that the representation of the subject is entirely due to the subject itself. Thus evidence is not what makes an impression or proposition true, but an evident proposition cannot but have a true proposition for its content and hence be true itself” (161).

A cognitive impression will be evident in that it represents all features of the object appropriate for the kind of object it is.

CI’s differ by themselves from other types of impressions; they have some kind of internal differentiating mark. Without this mark, we would have to rely on coherence between beliefs or some other such method. In such a case it would be inevitable that we would occasionally be wrong, and this would mean that we are not responsible for certain paths our lives go (because we were wrong with respect to some belief that influenced a choice, but being wrong about that belief was not our fault). This Stoics do not want to say this.

The only way to be completely responsible for our life is if we are able to avoid falsehood entirely.

Stoic Definitions of Cognitive Impressions

We get two versions of the definition of a καταληψις:
* SE’s and DL’s shorter version (two clauses)
* A more common, longer version (three clauses) The third clause is likely added from a debate as to whether CI’s have an internal differentiating feature.

The shorter version holds that an impression is cognitive if:
1) it comes from what is (apo huparchontos) and
2) it is imprinted and impressed in exact accordance with what is. (The impression must be clear and distinct.)

The requirement that it come from what is likely as the meaning of come from what is true (rather than come from a real object). To distinguish CI’s from other, noncognitive, impressions that are entirely true, the Stoics added the second clause. Then, because of debates with the Stoics, a longer definition was developed with a third clause:

3) it could not come about from what is not. “This, as we noted above, is taken to imply that an impression of this character could not be false…” (165).

Annas appears to take a different interpretation of (1) and (3), interpreting it to mean ‘from what is real’ and ‘from what is not real’, respectively. Indeed, if we look at SE’s account of CI’s, we see evidence to take ‘huparchein’ to mean ‘real’ rather than ‘true’. Consider 7.249: “The first of these is its coming about from a real thing; for many appearances strike us from what is not real, as in the case of crazy people, and these would not be apprehensive.” On the other hand, Cicero talks in terms of truth and falsity rather than existence. See 164-5 for Frede’s arguments in favor of the truth reading rather than existence reading.

The Criterion

How do CI’s constitute the criterion of truth?
* We can’t use them to certify the truth of any proposition.
* We can’t just consider some CI that corresponds to a belief that we want to test

Why? Because
* CI’s can only guarantee the content of their own propositional content
* If CI’s are only perceptual, they can only guarantee the truth of propositions that guarantee the truth of propositions that attribute a perceptual feature to an object. Also, there is no such thing as an impression that corresponds to a given proposition. One might have to go through a number of impressions to get to a CI. (You might have to go through a number of impressions of the man you’re walking toward until you get to a CI that the man is Socrates.) “Thus CI’s can’t be the criterion in the sense that we just have to look at our impressions to determine whether a proposition is true. It is, rather, by considering the proposition that we may get a clearer and clearer impression.
* Impressions aren’t pictures that can be examined introspectively but rather impressions are highly complex physical states; they’re imprints of objects in the world on our mind. So we cannot simply introspect as to whether the impression has the characteristics distinctive of CIs.

The distinctive mark that CIs have that marks them off from other impressions (and allows us to determine which impression is a CI and which isn’t) is the causal effect that it has on our mind. “The suggestion, then, is that the distinctive mark of cognitive impressions is a causal feature in that it makes the mind react in a distinctive way and that it is in this sense that the mind can discriminate between cognitive and noncognitive impressions” (168).

CI’s are called the criterion of truth because they can indirectly guarantee the truth of all other propositions known to be true. How? Because they give rise to general ideas (common notions; προληψεις) which in urn allow us to have further CI’s. For example, a CI of man leads to the common notion of man as a biped rational animal. This common notion is certified by (a) the CI’s which give rise to it and (b) the CI’s it gives rise to.

Looking at the Stoic account of common notions, it is clear that we don’t deliberately form common notions from CI’s. Our mind does this without our awareness of it. We just find ourselves with concepts that we didn’t have to start with.

Why does the mind assent to some impressions and not to others? There may be different answers, depending upon where one is in her cognitive development. Initially, it could be that CI’s cause the mind to accept them. Later, we may accept or reject impressions based upon the background of beliefs that we already have.

So it seems that the differentiating mark of CI’s is a causal, rather than a phenomenological, feature.

Cognition, Knowledge, and the Wise Man

The Stoics distinguish between knowledge, cognition, and mere belief.

Cognition: assent to a cognitive (in the wider sense) impression.
Opinion: assent to an impression that may or may not be cognitive
Knowledge: assent to cognitive impressions where the assent is of the sort of that firm such that one cannot be persuaded to withdraw the assent.

SO, one can’t have a false belief lest he be lead to accept the contrary of what he thought true via argument and dialectic.

All cases of cognition are cases of opinion or knowledge depending on whether they have the appropriate kind of assent. The average person will have nothing but beliefs because he cannot avoid any false belief and so his assent isn’t firm.

This leads the Stoics to say that no one has knowledge, while maintaining that it is still possible.

Skeptical Attack

The skeptics focused their attack on the doctrine of καταληψις. They took issue with the idea that a καταληψις (1) had a distinctive character such that there could not be an identical impression which was nonetheless false AND (2) by arguing that there are false impressions which have the characteristics of CI’s (vividness, etc) such that one could not distinguish it from a CI.

To (1) the Stoics respond that no two things are exactly alike and with training we can learn to distinguish the two objects. To (2), the Stoics can say that even in abnormal situations, we can distinguish between cognitive and noncognitive impressions and, further, it is a mark of deep abnormality if you cannot make such a distinction.