Aristotle and the Law of Identity

[BaalChatzaf]

I got a blurb on Aristotle and the Law of Identity from Wiki. Here it is:

Parmenides the Eleatic (circa BCE. 490) formulated the principle Being is (eon emmenai) as the foundation of his philosophy. Aristotle, by contrast, took the Principle of contradiction as his first principle, and does not refer explicitly to the Law of Identity, although the law is often attributed to him (particularly by the proponents of Ayn Rand's writings). His only apparent reference to the principle is in Book VII of the Metaphysics:

Now "why a thing is itself" is a meaningless inquiry (for—to give meaning to the question 'why'—the fact or the existence of the thing must already be evident—e.g., that the moon is eclipsed—but the fact that a thing is itself is the single reason and the single cause to be given in answer to all such questions as why the man is man, or the musician musical, unless one were to answer, 'because each thing is inseparable from itself, and its being one just meant this.' This, however, is common to all things and is a short and easy way with the question.) —

Metaphysics,

Book VII, Part 17

Has anyone ever pointed out Ayn Rand's error in attributing the law of identity to Aristotle?

Ba'al Chatzaf

Edited April 12, 2010 by BaalChatzaf

[tjohnson]

This person did. http://www.geniebust.../04e_ex01C.html

[9thdoctor]

This person did. http://www.geniebust.../04e_ex01C.html

I just checked out this guy’s site. Whoa. He has a big piece on the non-existence of Nazi gas chambers. http://www.geniebusters.org/915/04g_gas.html And a piece favoring “National Socialism” over “International Capitalism”. Wow. It’s a hell of a site, I’ll say that. http://www.geniebusters.org/915/03_postnazi.html

[tjohnson]

I also found this by Joseph Rowlands here;

To have an identity means to have a single identity; an object cannot have two identities. A tree cannot be a telephone, and a dog cannot be a cat. Each entity exists as something specific, its identity is particular, and it cannot exist as something else. An entity can have more than one characteristic, but any characteristic it has is a part of its identity. A car can be both blue and red, but not at the same time or not in the same respect. Whatever portion is blue cannot be red at the same time, in the same way. Half the car can be red, and the other half blue. But the whole car can't be both red and blue. These two traits, blue and red, each have single, particular identities.

The concept of identity is important because it makes explicit that reality has a definite nature. Since reality has an identity, it is knowable. Since it exists in a particular way, it has no contradictions.

This is definitely in conflict with wave-particle duality. I don't why he thinks something can't be knowable without the law of identity. We know a great deal about photons even if they act like waves sometimes and particles at other times.

[dan2100]

I also found this by Joseph Rowlands here;

To have an identity means to have a single identity; an object cannot have two identities. A tree cannot be a telephone, and a dog cannot be a cat. Each entity exists as something specific, its identity is particular, and it cannot exist as something else. An entity can have more than one characteristic, but any characteristic it has is a part of its identity. A car can be both blue and red, but not at the same time or not in the same respect. Whatever portion is blue cannot be red at the same time, in the same way. Half the car can be red, and the other half blue. But the whole car can't be both red and blue. These two traits, blue and red, each have single, particular identities.

The concept of identity is important because it makes explicit that reality has a definite nature. Since reality has an identity, it is knowable. Since it exists in a particular way, it has no contradictions.

This is definitely in conflict with wave-particle duality. I don't why he thinks something can't be knowable without the law of identity. We know a great deal about photons even if they act like waves sometimes and particles at other times.

I don't think it's a matter here of people being ignorant of the Law of Identity being unable to know things about the world, but that the Law of Identity is presumed in all knowledge.

Regarding wave/particle duality, also, I don't think this exactly conflicts with the Law of Identity or any of its corrollaries. In fact, even the way you put it -- photons sometimes behave one way, sometimes another -- seems no great stumbling block; sometimes the Sun is overhead, sometimes it's not. But more seriously, the real problem with wave/particle duality seems to me to be that it conflicts with intuition rather than logic.

[Reidy]

To answer the question in #1: yes, here on OL over three years ago: http://www.objectivistliving.com/forums/index.php?showtopic=2252&st=0&p=49941&hl=duns%20scotus&fromsearch=1entry49941

I believe this information first showed up in the Objectivist literature in Peikoff's dissertation in 1964.

[Leonid]

According to Aristotle the truly real is the individual thing determined in itself by its form (essence). This is amount to identity law.

[dan2100]

According to Aristotle the truly real is the individual thing determined in itself by its form (essence). This is amount to identity law.

I believe the passages one must look to are in Topics. I'm having trouble finding the exact passage that amounts to something like "a thing is itself." I think something similar is mentioned in his Metaphysics, Book VII... Of course, he doesn't come right out, if my memory's correct, and use the modern formulations, such as "Law of Identity" or "A is A."