But then a complete perception of an object would involve a faculty of intellect, right, not only sensory organs?
From my point of view, a "complete perception" of an object would be more a function of repeated observations, from different perspectives, at different distances,using all of the faculties of perception, but there is where I would draw the line, and as far as the process of drawing those observations into an opinion that is right or wrong, that part i would classify as "intellectual" and therefore no longer "perception."
So if there is a 'criterion' of horse, then it seems to me that it must depend on thought and memory. And I admit that I think that if Epicurus doesn't think that, then I'm not sure his view is plausible.
This is the point in the conversation where I go with DeWitt, who argues that in regard to concrete objects to which we are exposed over time we will indeed form a concept (mental picture) of a horse, and then use that concept in the future to apply the same "word" to new instances of four-legged animals when we see them, to form an opinion as to whether those animals or are or not horses. This is what Laertius hammers home, but in my view this is describing what is done *after* the five senses and feelings and anticipations have relayed their input to the mind. DeWitt's position seems to me to be that Laertius is confusing the process of "working with" proleptic input with the more important issue of "forming" proleptic input, and that the process of forming proleptic input to the mind is completely pre-rational, pre-conceptual, and actually is present as a faculty and in operation *before* we ever see our first horse, just as the eyes are operational and functional before we ever use them to see (and then in the mind) to classify anything at all.
It seems to me that Epicurus thinks opinions can be true or false, and not all opinions are about sensations. Sensations don't have to confirm an opinion for the opinion to count as true.
As to "not all opinions are about sensations" I would agree with that. We can definitely have opinions about opinions (adding layers upon layers there). And I would say that there is prolectic involvement in the assembling of opinions about opinions. But that proleptic invoilvement would not involve telling us which opinions are true, but would function more on the order of recognizing in the first place that arithmetic has some relationship to calculus about which to take notice.
In discussing today the issue of what Lucretius means about the gods not having a pattern by which to create the universe, it seemed to me that Lucretius should not be interpreted so much as taking the position that gods cannot create planets and the like from existing materials (I would expect Epicurus to take the position that they can in fact do things that we will be capable of one day). Rather, it seems to me that the emphasis is on that no one, gods or human, can do anything without their minds having the disposition to assemble experiences into more complicated constructs (the anthropomorphizing Don mentioned earlier today being an example). I would therefore see the example as implying that both gods and men must rely on Nature to provide the disposition and ability for a mind to construct abstractions, but the faculty of prolepsis is not any single abstraction which is formed, but the *capability* to form abstractions in the first place.
I would say that the meaning is more likely to be that were it not for the faculty of anticipations, the raw data presented by (1) the five senses (2) the feelings of pain and pleasure, and (3) previous anticipations would never be assembled into any abstractions whatsoever. To me, that distinction keeps the focus on prolepsis being a pre-rational, pre-cognitive faculty, and yet still gives it an important place in the formation and use of concepts.