Random Philosophy

[lorimt]

I juts ran across this while reading Avicenna.

"Moreover, if any thing is composed of two things, if one of the two things cam be found without the other, the other can be found without the first. An example of this is oxymel, which is composed of vinegar and honey: if vinegar can be found without honey, honey can be found without vinegar. Another example is the formed statue composed of bronze and the human form: if bronze can be found without the human form, the human form can be found without the bronze. This can be found by induction and has many examples."

I'm not buying into the induction bit without an actual proof, since I've seen too many 'proofs' of this sort by ancient philosophers. The concept, however, strikes me as very interesting, particularly the form/material bit. Does anyone have any counterexamples, or particularly interesting examples? My brain is wavering between "I've got it, it all makes sense, look how obvious this idea is," and "What about this case? This isn't true at all."

Of all the Avicenna I've worked through tonight, this was the bit that most caught my eye. It sort of sums up the rest however. I've found a tendency to alternate between "how interesting," and "you make no sense," though usually in regards to different arguments.

Comments

[kitty-tape.livejournal.com]

I don't think this works because it is saying if there exists an A without a B then there exists a B without an A. Now, if you said if for all A, A exists without B then, if B exists, there exists B without A. An example as to why the quantifier must be treated this way is as follows: if water can be found without a duck, then a duck can be found without water. This is clearly false if we consider that a duck is composed of water and therefore cannot be found without it. (Clearly, we can find water without a duck; it is what I prefer to drink.)

[ztbb.livejournal.com]

How about this: a house is composed of a ground floor and an upper floor. A ground floor may be found without an upper floor, but an upper floor may not be found without a ground floor. (Or, a variant: the CN Tower is composed of a tall structure and an observation deck. Tall structures may be found without observation decks, but not vice-versa.)

[sithjawa.livejournal.com]

What about philosophy and wanking? Wanking can be found without philosophy, for example on Schmack...

::runs away very very fast::

[easwaran.livejournal.com]

I think his statement has good methodological appeal (it doesn't make sense to say that something is made of two parts unless you can show that these parts actually exist independently of one another), but isn't the sort of statement that can - or should - be justified by evidence or induction.

The counterexample that came to my mind immediately on reading the statement was that a proton is made up of three quarks, but quarks can't exist separately. In my few minutes of thought, I decided this was actually a strong argument against the quark theory, and in favor of a theory that discusses various attributes of protons and neutrons without explaining them in terms of new, more fundamental particles. Although on second thought, the fact that quarks can exist in both hadrons and mesons does show that each type of quark can exist independently of each other, though not of all of them.

I think this principle is more on the lines of Occam's Razor. Ockham says "don't postulate an entity unless you absolutely need it to explain the world"; Avicenna says "don't postulate an entity if it always exists only in one particular combination" though he may not have phrased it this way. If you want to analyze a magnet as a combination of iron atoms aligned in a certain way, plus the "magnet ghost", you're not adding any explanatory power to your theory. The "magnet ghost" never appears anywhere except in a magnet, so anything that it's presence supposedly explains could have been attributed to the particular form of the iron, and not the magnet ghost.

I think Dave's example may be fixable by saying that you don't really have a "ground floor" and an "upper floor" but rather just several floors, any of which can exist independently of the others. None of them is essentially an upper floor. Thus, an "upper floor" isn't a new entity we postulate to explain the combination of a two-story house.

What I don't understand is why he didn't apply this to all combinations of things, but only combinations in which at least one component appears without the others. It sounds like he's allowing the possibility that "iron" is really made of two things: "iro" and "ron", neither of which occurs separate from the other, each of which is taken to explain different properties of iron. That sounds ridiculous to me.

[squirrelloid.livejournal.com]

It's you!

To construct a counter-example, you'll need to look in the set of thought constructs because for any real world things this will hold.

And i think they mean philosophical induction, which isn't as sound as mathematical induction, but is true 99.9% of the time. (The sun has risen every day of my life, therefore the sun will rise tomorrow).