Issues In The Meaning And Definition of Logic

Wasn't one of Epicurus's big gripes against Socrates that Socrates just ignored the commonly accepted definitions of words or he made up new definitions? To my memory, Epicurus was like "How can you even hold a conversation let alone an investigation of 'truth' with this guy?? He's just a jerk!"

Quote from Camotero

But how can logic be verified through the senses, if it is completely a mental thing. Wouldn't it be, logic should be constraint to material issues? Or that if it has to fly a bit into the ether, it should have a grounding back into maerial reality, otherwise it would be plain speculation about things that don't exist?

For me, it seems critical to ground logic in material reality and that's the purpose of the Canon. Think of the common example of "Bob is a man. All men are mortal. Therefore Bob is mortal." At least to my understanding, we need the Canon to provide evidence that Bob is a man and that all men are mortal, or neither of the two statements are verifiable and therefore the conclusion is not verifiable, even if it is "formally" correct. This is why I think it's important that the article linked to above in post #7 describes reasoning in the context of the scientific method.

To expose my ignorance, one question that I have as I begin to work my way through DeLacey: how do "signs" fit into this discussion? It seems that words are signs; what about "first mental images," concepts... what else can be considered a sign? Do the Stoics have a different idea of what constitutes a sign than the Epicureans do? Just defining the language with which to discuss logic and methods of inference is confusing!

I stumbled upon this quote online, though I'm not sure if it's helpful:

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"All instruction is either about things or about signs; but things are learnt by means of signs. I now use the word “thing” in a strict sense, to signify that which is never employed as a sign of anything else: for example, wood, stone, cattle, and other things of that kind. Not, however, the wood which we read Moses cast into the bitter waters to make them sweet, nor the stone which Jacob used as a pillow, nor the ram which Abraham offered up instead of his son; for these, though they are things, are also signs of other things. There are signs of another kind, those which are never employed except as signs: for example, words. No one uses words except as signs of something else; and hence may be understood what I call signs: those things, to wit, which are used to indicate something else. Accordingly, every sign is also a thing; for what is not a thing is nothing at all. Every thing, however, is not also a sign. And so, in regard to this distinction between things and signs, I shall, when I speak of things, speak in such a way that even if some of them may be used as signs also, that will not interfere with the division of the subject according to which I am to discuss things first and signs afterwards. But we must carefully remember that what we have now to consider about things is what they are in themselves, not what other things they are signs of. AUGUSTINE, De Doctrina 1.2." From the Heidlblog

Despite the anachronism it seems that this is what Epicurus was struggling against

I'm be very curious about that book I ordered. I think it will answer some questions we're posting here. Here is a section of a review specifically on Sedley's chapter:

David Sedley contributes a helpful chapter about “Epicurus on Dialectic,” in which he considers several ways in which Epicurus’ well-known rejection of the dialectical method reflects Epicurus’ own ontological commitments. One particularly noteworthy aspect of Sedley’s chapter is his discussion of the so-called ‘Bat Riddle’ that Glaucon mentions in Book V of the Republic (89-105), in which ‘a man who is not a man shoots and does not shoot a bird that is not a bird,’ etc. Sedley argues that this riddling description of the eunuch (who is both a man and not a man) who shoots (and misses) a bat (which both is and is not a bird, as it is a bird relative to its gift of flight but is not a bird insofar as it is viviparous) captures the Epicurean view that being is in all cases relative and aspectual, and hence not truthfully or meaningfully disclosed through the kind of dialectical investigation at play in, for example, Platonic division.

Quote from Don

Wasn't one of Epicurus's big gripes against Socrates that Socrates just ignored the commonly accepted definitions of words or he made up new definitions?

That actually sounds to me more like Cicero's gripe against Epicurus, that EPICURUS was not using words like pleasure in a standard way.... Don't hold me to that but I think so.

Quote from camotero

and reason is particular faculty of our own, how come reason is not part of the Canon of Truth? If you ask me, it seems more plausible to find truth in by way of reasoning as the article explains, and the canon is more a canon of morality, rather than of truth.

Camotero with all due respect and affection many of your comments in the recent posts above are (I am confident you are going to find) very off-base as to Epicurus' position. I think you're instinctively taking the majority Platonic / Aristotelian / Stoic position that logic is the center of good reasoning, and I think you're going to find that that (depending on the definition of "logic' and focusing in dialectical logic) is exactly what Epicurus rejected as the focus.

Of course working through these issues is exactly what we are here to do, so it will be fun.

However, this thread is already serving as an important reminder to me that it is going to remain a very good idea to jump up and down and shout and all the rest to READ DEWITT FIRST AND/OR EARLY because no one who reads DeWitt will be surprised or taken aback by any of these arguments that deprecate "logic." DeWitt drives home throughout the book how this rejection of Platonic logic is at the heart of his philosophy. So even now I would recommend reading DeWitt's chapters One (for the overview) and Seven and Eight for the focus on these canonical / logical issues. Although due to the way DeWitt presents things telescopically, the same issues appear at multiple places in the book and that's why I recommend the whole thing.

Now don't anyone misinterpret what I just wrote -- I am not chiding anyone. Going through these arguments is extremely helpful to everyone. But the real problem with approaching Epicurus through anyone but DeWitt - even trying to read Diogenes Laertius and Lucretius first - is that it's hard to pick up the significance of the full extent of Epicurus' revolution against virtually ALL who went before him. I am convinced that Epicurus' revolution wasn't based nearly as much on the role of "pleasure" as it was on these issues of the canon and the role of logic. The ethics of Epicurus are strictly secondary and derive from the physics, and the physics analysis is tightly tied to the canonics.

Of course the bitter truth is that most people are going to come here having read mainly the Cambridge and the Warren and the O'Keefe material. They are mostly as a result going to be so hamstrung on "absence of pain" that they have a long hill to climb to get to the real issues. But these issues of the canonical faculties and the role of logic/conceptual reasoning are where the real battle lies, in my humble opinion! And the opponents of Epicurus are almost more worked up about his rejection of "logic" than they are of his rejection of "virtue" and "religion" -- maybe more so, because the canonics/logic argument is the key to defeating their virtue/piety arguments.

LOL I see that I have just accused Camotero of not reading DeWitt, and now I see THIS from the new poll of what people have read:

Ha someone has some adjusting to do -- either I am dramatically mis-remembering what is in DeWitt, or I need to get to work on that Quiz to help test how closely people have really read what they think they've read

Maybe you skimmed chapters Seven and Eight Camotero? Or maybe DeWitt wasn't as convincing as I remember him being

Either way we'll figure it out and it will be fun doing so.

Don I appear to have access to the Sedley chapter on Dialectic but I have absolutely no confidence that I will be able to read it anytime soon, so I hope you'll lead us through that one by commenting when you get it.

Quote from Godfrey

how do "signs" fit into this discussion? It seems that words are signs; what about "first mental images," concepts... what else can be considered a sign? Do the Stoics have a different idea of what constitutes a sign than the Epicureans do? Just defining the language with which to discuss logic and methods of inference is confusing!

Godfrey if you are getting started in Philodemus I hope you will post all sorts of things like that in the Philodemus thread. Yes it appears that signs are a big issue, as well as the terms "contraposition" and also "reasoning by analogy"

Articulating this question of what signs means and how the Epicureans took a position on them is going to be key to unwinding all these issues. They clearly took the position that "contraposition" is not the key to truth.

One way of stating what i remember the ultimate point to have been is that Plato and the boys were taking the position that nothing can be said to be "true" unless the proposition could be stated in some form of symbolic logic (if A=B and B=C then A=C, might be an example, but I think their examples were much more complex).

The Epicureans took the position that truth has to be "defined" in terms of evidence from the canonical faculties, not from symbolic logic.

But that is a very primitive way of stating the issue and our goal ought to be to make things a lot more clear than that.

Quote from camotero

perhaps that game wouldn't make sense at all to me. I may be at fault of not remembering it well enough

1 - I first read DeWitt over ten years ago now and I frequently misremember it.

2 - Plus I suppose to be clear about deWitt, his goal and his merit is in providing the wide overview that gives us an orientation, and the book isn't nearly long or detailed enough to give us all the raw material and argument that we'd like to have, so that's where we have to fill in the gaps. I think DeWitt's usually right or close to right in most of his views, but in all of the details we have to work through them ourselves.

Here's one section of DeWitt that addresses what I remembered about Socrates and about dialectic. Interestingly, logic doesn't appear in the index to Epicurus and His Philosophy:

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As for the third branch of Platonic studies, dialectic, the evidence for Epicurus' familiarity with it is the express and almost total rejection of it. The grounds of this rejection were both ethical and intellectual. It is on record that he condemned the irony of Socrates.50 It is not difficult to discern the reasons for this. The pretence of ignorance is a form of dishonesty and inconsistent with that absolute frankness (parresia) by which Epicurus set great store, as will be shown under the head of the New Virtues. Yet even assuming that Socrates felt himself to be genuinely ignorant of the nature of piety or justice, he was deliberately concealing his mastery of a devastating skill in debate, which could only result in the humiliation of the hapless interlocutor in the presence of witnesses. This was totally opposed to that disinterested concern (kedemonia) for the good of the instructed which was required of the Epicurean teacher. If Cicero disagreed with Epicurus about the condemnation of irony, this was but natural, because, whether as trial lawyer or political orator, the ability to make his victim writhe under mental punishment was a precious part of his equipment. In the judgment of Epicurus the Second Philippic of Cicero and the speech of Demosthenes On the Crown would have seemed to represent oratory at its ethical worst, whether because of cruelty of intention on the part of the speakers or the love of havoc on the part of the listeners. A second evil of dialectic was the tendency to become eristic and argue for victory instead of truth. This was incompatible with the Epicurean considerateness (epieikeia) for the feelings of others, which fore- shadowed the Golden Rule of Christianity. It was thus no accident that Epicurus, in the manifest division of labor which prevailed in the mature organization of the Garden School, reserved for himself the task of refuting the Megarians,51 with whom eristic was a specialty. Only the head of the school seemed capable of dealing with methods so contrary in spirit to the new philosophy. The intellectual grounds for rejecting dialectic were equally funda- mental. Epicurus denied categorically each of its four assumptions, first, that reason was the criterion, second, that sensations were undependable, third, that phenomena were shifting and deceptive, and fourth, that the only real and eternal existences were the ideas. The reality of the ideas he denied on the ground that nothing exists except atoms and empty space. In place of reason he declared Nature to furnish criteria of truth and he held the Sensations, supplemented by the Feelings and innate notions (Anticipations), to be direct and immediate contacts with external reality, whether physical or social. Thus dialectic became a superfluity. The rejection of Plato's teachings is almost total.

That footnote 50 after Socrates refers to Cicero's Brutus (85.292):

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"But I made some remarks," said Atticus, "which I had several times a mind to mention; only I was loath to interrupt you. As your discourse, however, seems to be drawing towards an end, I think I may venture to out with them."—"By all means," replied I.—"I readily grant, then," said he, "that there is something very humourous and elegant in that continued Irony, which Socrates employs to so much advantage in the dialogues of Plato, Xenophon, and Aeschines. For when a dispute commences on the nature of wisdom, he professes, with a great deal of humour and ingenuity, to have no pretensions to it himself; while, with a kind of concealed raillery, he ascribes the highest degree of it to those who had the arrogance to lay an open claim to it. Thus, in Plato, he extols Protagoras, Hippias, Prodicus, Gorgias, and several others, to the skies: but represents himself as a mere ignorant. This in him was peculiarly becoming; nor can I agree with Epicurus, who thinks it censurable. But in a professed History, (for such, in fact, is the account you have been giving us of the Roman Orators) I shall leave you to judge, whether an application of the Irony is not equally reprehensible, as it would be in giving a judicial evidence."—"Pray, what are you driving at," said I,— "for I cannot comprehend you."

All of what I see you raise are good questions so while I appreciate your last statement I firmly think the discussion we're having is very valuable. I do think, however, in general, that we are suffering from the difficulty of really having a bright line definition of many of these words (logic, reason, dialectic, dialectical logic, etc). And much of the reason for that is they these words are commonly used in very similar ways, so each discussion about each word almost requires a clarification each time it is used.

Quote from camotero

So, rhetoric? Which may have been considered logic, but it's not. Am I wrong?

Rhetoric is another word that in my view isn't so clear in common usage.

Quote from camotero

So he is not talking at all about reason, as in what we understand as logic

Just citing that to reinforce the issue that "reason" seems to have a number of connotations that may or may not make it similar in usage as logic depending on context.

Quote from camotero

Also, it's been stated over and over again that while that sensations can and are always true (in that they bring a pure impression) they can be, as DeWitt puts it, valueless as a criterion (the round/square tower example). And how are we going to discern this if not by reason?

Of all the comments this is probably the most important to articulate better. We confirm that the tower is in fact square by walking toward it, viewing it from different angles, touching it, etc. It is never reason *alone* which does the confirming, it is the reliability of subsequent multiple sensations. There's a really good cite from Epicurus directly on that point (that the reliability of our conclusions / opinions comes from the repeatability of the sensation) that if my mind were quicker I'd like to post, but can't. If someone else can I hope they will add this to the thread.

Now someone may want to argue, "Well, comparing multiple sensations to see which is reliably repeated IS a form of "reason" or even "logic!" If someone goes down that path then they've really got to disentangle what they mean by reason and logic, because such a wide definition essentially converts every example of looking for consistency into reason and logic and that clearly is not Epicurus' target.

Quote from camotero

Otherwise we are perceiving reality, alright, but if we don't process it with reason, we're no different than other animals.

Ok now on that point it is my position (and I think Epicurus') that there IS no essential difference between humans and other animals. And that precise argument is stated very clearly by Cicero who complains that Epicurus reduces us to the state of animals by not worshiping reason/logic as he (Cicero) does. Can't easily remember the cite there but I think it's in Academic Questions.

Quote from camotero

: "How do we know something is true? I can feel when something is true". I don't think this is true, but I'm open to be corrected. I'm pretty sure the person who said this didn't mean it and said it rhetorically or lightly as no one objected it.

This is very valuable for you to call this into question. Are you talking about something Elayne said? I don't suppose you have a time cite do you? I remember being uneasy with certain formulations of some of that discussion and it might be that it would be good to make some notes on that episode to clarify. I am remembering that it was Elayne who said something like that and (if I recall) I considered it a reasonable formulation of the "feeling of certainty" that we do in fact get when we are legitimately convinced that our conclusion is correct. And in a way (depending on the words that were used) it is correct to argue that certainty / confidence in Epicurean terms comes from our ability to confirm our opinions through the data we observe through the senses and all the canonical faculties.

It is also possible that what you're referring to was in discussion of "abstractions'" and I also think there may have been some statements made at times that may have been more critical of abstractions than would be warranted. But there is an important point there too about the limitations of abstractions, so it would be necessary to pull out the precise statements and consider them carefully.

Anytime you (or anyone) feels like certain statements in the podcast might warrant clarification or revision please make note of it (preferably in the discussion for that episode) and try to record the time it appears and we'll go back and address those. It would be very valuable for everyone to do that.

Quote from Camotero

The last line quoted above is a testament to how reason is not to be disregarded, isn't it? Perhaps this is the type of true reason that we won't be able yo get by without?

If this reason isn't logic, or formal logic, could we agree that it could be "critical thinking"?

This seems to be a key distinction! Logic that is used to win arguments may lead to victory but not necessarily truth. Epicurus placed high value on wisdom and/or prudence, which I think can be equated to critical thinking. Reasoning of this sort has the goal of living well, not necessarily winning arguments.

Of course this begs the question: "how do you define prudence or critical thinking?" Film at 11

Here's the quote I was looking for above about the repeatability of the senses being the guarantee of their accuracy. Someone might say that's not exactly the same point as being discussed, but I think it pretty much is, because it seems implicit that if we're talking about the truth of our senses we're talking about the truth of the opinions that we can confidently reach based on what the senses repeatedly tell us:

**Diogenes Laertius, _Lives of Philosophers,_ X.31:** They reject the dialectic as superfluous; holding that in their inquiries the physicists should be content to employ the ordinary terms for things. Now in _The Canon_ Epicurus states that the sensations, the prolepses, and the passions are the criteria of truth; the Epicureans generally make perceptions of mental presentations to be also standards. ... Every sensation, he says, is devoid of reason and incapable of memory; for neither is it self-caused nor regarded as having an external cause, can it add anything thereto or take anything therefrom. Nor is there anything which can refute sensations or convict them of error: one sensation cannot convict another and kindred sensation, for they are equally valid; nor can one sensation refute another which is not kindred but heterogeneous, for the objects which the two senses judge are not the same; nor again can reason refute them, for reason is wholly dependent on sensation; nor can one sense refute another, since we pay equal heed to all. And the reality of separate perceptions guarantees the truth of our senses. But seeing and hearing are just as real as feeling pain. Hence it is from plain facts that we must start when we draw inferences about the unknown. For all our notions are derived from perceptions, either by actual contact or by analogy, or resemblance, or composition, with some slight aid from reasoning. And the objects presented to madmen and to people in dreams are true, for they produce effects – i.e., movements in the mind – which that which is unreal never does.