eh

Apparently different systems of logic have been setup to deal with the quantum world. The law of identity, no excluded middle, and law of non contradiction are discarded. Such logic does indeed sound like complete nonsense.

I suppose the wave funtion of an electron can be everywhere, much like how any object in the classic world (ie. a house, planet, stars etc.) occupies more than one place at the same time. The wave is just a mathematical concept of where the electron might be, no?

AdamWho

This doesn't pose a problem for the law of identity at all.
To say an electron is here or there with absolute certainty is to apply properties to electrons which they don't have.
Then to say that electrons violate the law of identity because they don't act the way you expected is like a straw-man fallacy.
Your implied assumptions were incorrect, no special logic necessary.

John Page

Um, er:

How about a system of logic where nothing is absolutely (or infinitely, if you prefer) true and nothing is absolutely/infintely false. Truth and falsity values would thus lie on a continuum joining these two theoretical values.

Thus we have the system of infinitely valued logic. Of course, Zeno would have much fun arguing about something that was half true and then made more accurate so it was halfway beetween halfway true and infinitely true....

I agree with Keith's comment "There are numerous systems of 'logic' which are based on incorrect, false, or fictitious premises. " Question is, can we tell? It seems to me we will accept the system of logic that seems to make most sense to us. Now about this theory that the earth is a spheroid....

Cheers, John

Hugo Holbling

Rorty doesn't merely avoid this difficulty; he dances a veritable jig upon its grave. I'm looking forward to your reaction, Keith.

Keith Russell

Hugo:

My reaction...to what?

How should I react to your claim (an unsupported claim, at that)that Rorty 'danced a jig' on this argument's 'grave'?

I haven't read much Rorty, but your analogy doesn't make it sound like Rorty killed the argument, merely that Rorty joined in celebrating its death.

I would rather react to the person who actually claims to have killed the argument, not react to someone (I guess Rorty) who merely 'danced upon its grave'.

So, to whose claims should I react?

Keith.

Dominus Paradoxum

The laws of logic are not tautologies. To say that 'a' just happens to be 'a' is a tautology, but to say that 'a' cannot differ from itself is to make a genuine assertion about the world. That is a common mistake that so-called 'analytic' philosophers make. As Blanshard said, it is a fallacy to suppose that a proposition says nothing just because it says something about everything. And by the way, we're getting into the a priori / a posterori distinction here. Now, it is true that logical laws are not known independently of experience, but they are not justified by it.

P.S.: To the guy who said quantum mechanics can do without logic: Can it both do without logic and not do without logic? If logical laws aren't universal, why not? When you hear scientists talk about an electron being 'in many places at once', they are talking about distinct parts of a probability wave. Veiwed as such, there is no contradiction.

Seeker196

I think you're getting sidetracked by the electrons 'fuzziness' in space.

I'm more intrigued by its fuzziness in time.

We can say, until it has been measured, it has X chance of being here or there, and a non-zero chance of being anyplace.

But how can we explain the theoretical 'time travelling' or 'time oscillating' property of an electron without throwing out the excluded middle or saying that it has a 'quantum limit'? It has an X chance of being anyWHEN as well.

Parts of a probability wave?:

We can speak of probability waves as having zones of 'high probability' and low but never zero....but there is never a zero chance of the electron being detected somewhere....so wouldn't it be more accurate to say that the pre-measurement probability wave is the size of the universe since it can appear anywhere?

John Page

Interesting. Do you affirm that the Law of Identity says that "a" cannot differ from itself? Clearly, a thing is itself - but isn't saying that "its not something else" mere repetition? If it's not itself then the LOI doesn't apply anyway thus the LOI is tautological.

Cheers, John

AdamWho

Logical identities are tautologies. If you look at the arguments against them being tautologies you will find people making assumptions; basically strawman and red herring fallacies.

The same argument as before:
This doesn't pose a problem for either the excluded middle or contradiction identities at all. To say an electron is here or there with absolute certainty is to apply properties to electrons which they don't have.
Then to say that electrons violate the logical laws because they don't act the way you expected is like a straw-man fallacy.
Your implied assumptions were incorrect, no special logic necessary. Besides bringing in theoretical assertions would be a red herring fallacy.

Yes, MATHEMATICALY the wave function never goes to zero and is ultimately the size of the universe, but in reality they are found in a pretty small box. Arguing that electrons (or any physical object) have the property, that they follow the math with 100% accuracy is to make a false assumption.

Keith Russell

Greetings:

The law of identity (A = A, or A is A) is tautological.

(But that doesn't make it untrue or irrelevant, IMO.)

Keith.