Deduction - Revision history

Hannibal at 19:59, 18 September 2008

Hannibal — Thu, 18 Sep 2008 19:59:38 GMT

←Older revision		Revision as of 19:59, 18 September 2008
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	'''Deductive Logic''' is the method of non contradictory identification. It is based on the classical [[The Laws of Classical Logic\|axioms]] of Aristotelean logic. ''Deductive arguments'' are akin to mathematical equations: they present a series of categories or definitions in a series of equivalencies. For this reason, the conclusion of a deductive argument necessarily follows from its premises, in the same way that ''4'' follows from the "premises" of ''2+2=''. In the opinion of this author, the most elegant form of a deductive argument is Aristotle's syllogistic logic, or [[Classical Logic\|classical deductive logic]].		'''Deductive Logic''' is the method of non contradictory identification. It is based on the classical [[The Laws of Classical Logic\|axioms]] of Aristotelean logic. ''Deductive arguments'' are akin to mathematical equations: they present a series of categories or definitions in a series of equivalencies. For this reason, the conclusion of a deductive argument necessarily follows from its premises, in the same way that ''4'' follows from the "premises" of ''2+2=''. In the opinion of this author, the most elegant form of a deductive argument is Aristotle's syllogistic logic, or [[Classical Logic\|classical deductive logic]].

-	Generally, it is held by logicians that deductive arguments work from general rules to specific conclusions. For example~~, consider this~~ categorical syllogism:	+	Generally, it is held by logicians that deductive arguments work from general rules to specific conclusions. This is a childish oversimplification of what deduction is. For example while the following categorical syllogism goes from the general to the specific:
	<pre>		<pre>
	All humans are mortal		All humans are mortal
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	Therefore, Socrates is mortal		Therefore, Socrates is mortal
	</pre>		</pre>
-	~~This syllogism works from a general rule: "all humans are mortal" to a specific conclusion: "Socrates is mortal".~~ '''~~However,~~ it is not necessary that deductive arguments move from general or universal statements, to specific or particular statements''' , for example, a deductive argument ~~can work~~ from particular premises~~, consider this disjunctive syllogism~~:	+	'''...it is not necessary that deductive arguments move from general or universal statements, to specific or particular statements''' , for example, the following disjunctive syllogism/deductive argument works from particular premises to a general conclusion:
	<pre>		<pre>
	If Socrates if human, then Socrates is mortal		If Socrates if human, then Socrates is mortal

Hannibal at 19:57, 18 September 2008

Hannibal — Thu, 18 Sep 2008 19:57:24 GMT

←Older revision		Revision as of 19:57, 18 September 2008
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	Therefore, Socrates is mortal		Therefore, Socrates is mortal
	</pre>		</pre>
-	This syllogism works from a general rule: "all humans are mortal" to a specific conclusion: "Socrates is mortal". ~~'''Bold text~~''' However, it is not necessary that deductive arguments move from general or universal statements, to specific or particular statements ~~'''Bold text~~''', for example, a deductive argument can work from particular premises, consider this disjunctive syllogism:	+	This syllogism works from a general rule: "all humans are mortal" to a specific conclusion: "Socrates is mortal". '''However, it is not necessary that deductive arguments move from general or universal statements, to specific or particular statements''' , for example, a deductive argument can work from particular premises, consider this disjunctive syllogism:
	<pre>		<pre>
	If Socrates if human, then Socrates is mortal		If Socrates if human, then Socrates is mortal

Hannibal at 19:56, 18 September 2008

Hannibal — Thu, 18 Sep 2008 19:56:51 GMT

←Older revision		Revision as of 19:56, 18 September 2008
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-
	'''Deductive Logic''' is the method of non contradictory identification. It is based on the classical [[The Laws of Classical Logic\|axioms]] of Aristotelean logic. ''Deductive arguments'' are akin to mathematical equations: they present a series of categories or definitions in a series of equivalencies. For this reason, the conclusion of a deductive argument necessarily follows from its premises, in the same way that ''4'' follows from the "premises" of ''2+2=''. In the opinion of this author, the most elegant form of a deductive argument is Aristotle's syllogistic logic, or [[Classical Logic\|classical deductive logic]].		'''Deductive Logic''' is the method of non contradictory identification. It is based on the classical [[The Laws of Classical Logic\|axioms]] of Aristotelean logic. ''Deductive arguments'' are akin to mathematical equations: they present a series of categories or definitions in a series of equivalencies. For this reason, the conclusion of a deductive argument necessarily follows from its premises, in the same way that ''4'' follows from the "premises" of ''2+2=''. In the opinion of this author, the most elegant form of a deductive argument is Aristotle's syllogistic logic, or [[Classical Logic\|classical deductive logic]].

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	Therefore, Socrates is mortal		Therefore, Socrates is mortal
	</pre>		</pre>
-	This syllogism works from a general rule: "all humans are mortal" to a specific conclusion: "Socrates is mortal". '''Bold text'''However, it is not necessary that deductive arguments move from general or universal statements, to specific or particular statements'''Bold text''', for example, a deductive argument can work from particular premises, consider this disjunctive syllogism:	+	This syllogism works from a general rule: "all humans are mortal" to a specific conclusion: "Socrates is mortal". '''Bold text''' However, it is not necessary that deductive arguments move from general or universal statements, to specific or particular statements '''Bold text''', for example, a deductive argument can work from particular premises, consider this disjunctive syllogism:
	<pre>		<pre>
	If Socrates if human, then Socrates is mortal		If Socrates if human, then Socrates is mortal

Hannibal at 19:56, 18 September 2008

Hannibal — Thu, 18 Sep 2008 19:56:25 GMT

New page

'''Deductive Logic''' is the method of non contradictory identification. It is based on the classical [[The Laws of Classical Logic|axioms]] of Aristotelean logic. ''Deductive arguments'' are akin to mathematical equations: they present a series of categories or definitions in a series of equivalencies. For this reason, the conclusion of a deductive argument necessarily follows from its premises, in the same way that ''4'' follows from the "premises" of ''2+2=''. In the opinion of this author, the most elegant form of a deductive argument is Aristotle's syllogistic logic, or [[Classical Logic|classical deductive logic]].

Generally, it is held by logicians that deductive arguments work from general rules to specific conclusions. For example, consider this categorical syllogism:
<pre>
All humans are mortal
Socrates is human
Therefore, Socrates is mortal
</pre>
This syllogism works from a general rule: "all humans are mortal" to a specific conclusion: "Socrates is mortal". '''Bold text'''However, it is not necessary that deductive arguments move from general or universal statements, to specific or particular statements'''Bold text''', for example, a deductive argument can work from particular premises, consider this disjunctive syllogism:
<pre>
If Socrates if human, then Socrates is mortal
Socrates is human
Therefore, Socrates is mortal
</pre>

We can call a deductive logical system an a priori system. This means that we can make up such a system without any observation or experimental examination.We can create a set of categories like squares or circles or letters, and a set of self consitent rules that follow a set of definitions, all without having to ever experience such "things".

http://candleinthedark.com/brain.gif Philosophers like to say that a "brain in vat" set apart from the rest of the universe could create an a priori system.