Sunday, March 17, 2013

Aristotle on Logic

When it comes to learning logic Aristotle is one of the founding fathers.  If you want to study logic a great place to start is Aristotle's collective work called the Organon traditionally made up of 8 different books: The Categories, On Interpretation, Prior-Analytics, Posterior-Analytics, Topics, Sophistical Refutations, Rhetoric*, and The Poetics*.  The last two are the ones that many modern philosophy/logic students often don't consider logical works, and it seems like these last two were just kind of thrown into the mix.  Sophistical Refutations is kind of like a text on anti-logic, a kind of how to spot the sophistical, empty arguments.  Of course, these works cover a wide range of logic and Aristotle's works in general cover a very broadly defined concepts of logic and philosophy.  There's no way I or anyone else could even try to attempt to cover every bit of these works but I've been listening to the History of Philosophy podcast, and Professor Adamson gives a nice overview of these works.  He talkes about how ancient philosophy students would start their foray into logic and philosophy with these works.

So far the podcast, as I've been going through it, has only given a broad overview of the logical works. To me, the most interesting book is the first one listed, The Categories.  In general, it's about categorizing various things.  The categories for different objects are listed as: substance, quality, quantity, relation, place, time, position, state, action, and being acted upon.  How certain parts a thing are essential to that that thing, and some are accidental.  It may seem silly but there's a problem I have with this.  One of the concepts within the philosophy of language is that words are given their meaning through a somewhat arbitrary process.  Prof Adamson uses the example of a giraffe quite often, so I'll follow his example.  I'm assuming everyone of my readers knows what a typical giraffe looks like.  One of the examples is a giraffe painted blue, so we have a blue giraffe, but that's just an accidental characteristic of that particular giraffe, or if there was a giraffe with a broken foot.  Those are accidental characteristics of giraffes.  So here's my question, one would assume that a long neck and legs would be considered essential characteristics of giraffes.  However, what if I told you that I had a short-necked short-legged giraffe?  What makes what I'm calling a giraffe?  Me calling it a giraffe?  According to some concepts of linguistics that's part of what makes it a giraffe.

The next on the list, On Interpretation is also quite interesting.  To me, it has one of Aristotle's most important contributions to logic and philosophy.  I've always heard it called the "Law of Non-contradiction" though Prof Adamson doesn't specifically mention it.  In general, this particular text is about negation and how to make statements and syllogisms.  I don't have the space to explain all that but I would like to talk a little about non-contradiction.  According to the professor of the logic course that I was taking through negating a statement isn't as easy as it appears.  The most straightforward method is to append the statement with "it is not the case that..."  So, the non-contradiction idea is this: two statements that are contradictions of each other cannot both be true at the same time.  For example, the statements "giraffes exist" and "it is not the case that giraffes exist," cannot both be true at the same time.  Obviously, at some time in the future or in the past giraffes may or may not exist, but at the same time they cannot both exist and not exist at the same time.  Though according to Prof Adamson, it seems that Aristotle leaves an exception to this idea, namely, for statements about the future.  For example, the statement "I will win the lottery tomorrow" is about the future and it is both true and not true at the same time.  Tomorrow, when I'm taking a bath in gold and jewels like Scrooge McDuck, I still can't say that statement was true or false just because it ends up coming true doesn't mean that when it was made it was true.