Aren\'t Tautologies Anathema to Logicians?

Is the scientific method real?

How can something use it\'s own process to prove it\'s own process?

How can science prove logic?Or mathematics?

At least I can feel God, But I\'m starting not to believe in this whole science thing. Can anyone prove these things to me

Cody, Yahoo Answers [2/25/2010 3:41:38 PM]

<-- intro end -->Hilarious--this guy posts this question on Yahoo! Answers that I\'ve been wondering about for years--how can one justify Logic without resorting to Logic. Saying that \"logic works because it is logical\" is a tautology of the first magnitude, and as a world model, Logic is especially vulnerable to this. Other models don\'t require one to reject tautological statements (some even encourage them) but Logic surely does!

This fellow didn\'t phrase his question very well, and it had a religious slant. In response, about seventy folks nearly broke themselves trying to show him how dumb he was. It\'s amazing how close they come to answering, and how far off others all--also amazing how much vitriol there is!

Choice responses:

\"One of the great paradoxes of logic is that the only way to meaningfully prove or disproof the utility of logic would be to use logic...\"
[fine, fair enough so far, but then he adds],
\"but this only serves to highlight how very important logic is.\"

\"I can prove that your grammar sucks moose cock.\"
[This is more or less the more common response]

\"The scientific method works. Even the Bible says that you shall know every tree by its fruits.\"
[Which is a nice response to the second half of the question, but completely misses the interesting bit]
\"Aren\'t fundies the same assclowns that claim the bible is true because it says so?\"
[Almost a good point, except that a purely Biblical model isn\'t under any obligation to avoid tautology, unlike a Logical one]
And then, ultimately, two really solid answers:

How can science prove logic?Or mathematics? \"It doesn\'t. It\'s the other way around. The so-called \"propositional calculus\" is a formal system that defines the logical process. Mathematics is an extension of this process. Both are abstract tautologies; that is, they\'re true by virtue of the meaning of the words. These abstractions can often be applied by scientists to derive conclusions about the real world.\"
and, a full month later:
\"Well, actually she (he?) has a truly valid point there... This circular argument omnipresent in scientific theory was (I think) first challenged by a guy called Paul Feyerabend\"
[Who, wikipedia says, was an Epistemological Anarchist, and is someone that I need to check out, I thnk]