Thursday, November 07, 2019

Necessary v Sufficient


My previous entry deals with the necessary versus the contingent, or what is of necessity versus what is of the contingent.

This entry:

Necessary versus Sufficient conditions

Philosopher Blackburn explains...

'If p is a necessary condition of q, then q cannot be true unless p is true. If p is a sufficient condition of q, then given that p is true, q is so as well.' (73).

Blackburn provides the example:

Steering well is a necessary condition of driving well... (73).

But it is not sufficient, as one can steer well, but be an overall bad driver. (73).

Perhaps, one steers very well, but is overly occupied by texting while driving. (My add, and not my practice)

This concept from Blackburn with the use of symbolic logic, provides a level of complexity, yet consistent and logical at the same time. But providing a true example provides another level of difficulty.

A solid/true example

Infinite attributes (a) are a necessary condition of infinite nature (b).

Infinite attributes (a) are a necessary condition of infinite nature (b), then infinite nature (b) cannot be true unless infinite attributes (a) are true. If infinite attributes (a) are a sufficient condition of infinite nature (b), then given that infinite attributes (a) are true, then infinite nature (b) is so as well.

BLACKBURN, SIMON (1996) Oxford Dictionary of Philosophy, Oxford, Oxford University Press.

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