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Kerrie
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For those of us who are still learning and understanding philosophy, can we differentiate logic in the most simple terms?
Originally posted by Kerrie
For those of us who are still learning and understanding philosophy, can we differentiate logic in the most simple terms?
Originally posted by Tom
On the other hand, a prescriptive law is a statement of how something should be done, as in the laws set forth by a legislature. They can be broken and changed. The study of the descriptive laws of reason (how people do, in fact, reason) is not logic, but psychology. But the study of the prescriptive laws of reason (how people ought to reason) is logic.
[?]So, we are interested in the latter—the prescriptive laws of reasoning.
Correct. That will be our definition of logic throughout this study[/I] [/B]
Originally posted by Kerrie
so who or what determines "should" be done? or how it should be done?
Some inferences are impeccable.
Consider:
(1) John danced if Mary sang, and Mary sang; so John danced.
(2) Every politician is deceitful, and every senator is a politician; so every senator is deceitful.
(3) The tallest man is in the garden; so someone is in the garden.
Such reasoning cannot lead from true premises to false conclusions. The premises may be false. But a thinker takes no epistemic risk by endorsing the conditional claim: if the premises are true, then the conclusion is true. Given the premises, the conclusion follows immediately--without any further assumptions that might turn out to be false. By contrast, it would be very risky to infer that John danced, given only the assumption that Mary sang. More interesting examples include:
(4) John danced if Mary sang, and John danced; so Mary sang.
(5) Every hairless biped is a bird, Tweety is a hairless biped; so Tweety can fly.
(6) Every human born before 1850 has died; so every human will die.
Inference (4) is not secure. Suppose John dances whenever Mary sings, and he sometimes dances when Mary doesn't sing. Similarly, (5) relies on unstated assumptions--e.g., that Tweety is not a penguin. Even (6) falls short of the demonstrative character exhibited by (1-3). While laws of nature may preclude immortality, it is conceivable that someone will escape the grim reaper; and the conclusion of (6) goes beyond its premise, even if it is (in some sense) foolish to resist the inference.
Appeals to logical form arose in the context of attempts to say more about this intuitive distinction between impeccable inferences, which invite metaphors of security and immediacy, and inferences that involve a risk of slipping from truth to falsity.
Originally posted by scott_sieger
Philisophically speaking (ha I love the length of that word)
in particular:Such reasoning cannot lead from true premises to false conclusions. The premises may be false. But a thinker takes no epistemic risk by endorsing the conditional claim: if the premises are true, then the conclusion is true. Given the premises, the conclusion follows immediately--without any further assumptions that might turn out to be false. By contrast, it would be very risky to infer that John danced, given only the assumption that Mary sang. More interesting examples include:
this is correct as long as one realizes that one of the premises is that ((A-->B)&A)-->B is true for all statements A and B. or you could say by definition of -->.Given the premises, the conclusion follows immediately--without any further assumptions that might turn out to be false.
Originally posted by Kerrie
For those of us who are still learning and understanding philosophy, can we differentiate logic in the most simple terms?
check out http://mathworld.wolfram.com/PropositionalCalculus.html. it gives some axiom schemata for formal logic. i guess most people would say that (11), modus ponens, is the most important one.I would say that it is deductive and inductive arguments from previously stated points that theorize the wrong of a system/design, which is not supposed to be based on emotion or whim but is often substituted for those purposes and principles.
Originally posted by phoenixthoth
check out http://mathworld.wolfram.com/PropositionalCalculus.html. it gives some axiom schemata for formal logic. i guess most people would say that (11), modus ponens, is the most important one.
these all seem like whims to me though they don't seem to be based on emotion. however, once you accept those axiom schemata which i could call whims, the theorems that follow from them are not of the whim variety.
Originally posted by Kerrie
For those of us who are still learning and understanding philosophy, can we differentiate logic in the most simple terms?
Originally posted by Loren Booda
Have any of you heard John Archibald Wheeler's argument that the physical universe is reducible to binary logic?
Can you give a reference or links for this? I'd like to know his argument.Loren Booda said:Have any of you heard John Archibald Wheeler's argument that the physical universe is reducible to binary logic?
Can you give a reference or links for this? - Canute