Anyone can become angry — that is easy; but to be angry with the right person, to the right degree, at the right time, for the right purpose and in the right way — that is not easy. — Aristotle
20090308
fortune
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weblog d'un abbe 
All dogs are mortal.
Aristotle is mortal.
Therefore, Aristotle is a dog.
Comment by edwinhere — 20090316 @ 1838
Sorry bad logic. Aristotle can be a dog, if he is really a dog, or all mortals are dogs.
Comment by abbe — 20090316 @ 1906
Yup. Not all mortals are dogs. The fallacy I made is called abductive reasoning, a.k.a guilt by association. It sounds obviously wrong, because we know Aristotle was human. Consider this:
All men are mortal.
Aristotle is mortal.
Therefore, Aristotle is a man.
Now it is slightly less obvious. This line of reasoning is wrong too, because like you said, even dogs & fish & .. are mortal, so Aristotle could just as easily be a dog or a fish or..
In protein function prediction, the only popular method used, uses abductive reasoning. It goes something like this:
All proteins with function A has a sequence S
Protein X has a sequence S
Therefore Protein X has function A.
So protein function prediction is not very accurate.
In future, when we will be able to simulate quantum many body problems on parallel computers, we will be able to make the computer think like this:
All proteins with a sequence S has function A
Protein X has a sequence S
Therefore Protein X has a function A
And such deductive reasoning will be more accurate.
Comment by edwinhere — 20090316 @ 2047
That abductive reasoning is wrong, because its base is wrong. Just think this way:
Dog derived from Mortal.
Aristotle derived from Mortal.
implies Dog and Aristotle aren’t necessarily the same.
So you’re using totally wrong logic. Similarly you can s/Dog/Man/.
Comment by abbe — 20090316 @ 2111