39

Logic 39 The criterion of inconceivability

Leibniz was as Hamilton says "nothing new" since it was no more than an utterly unsucessful attempt to define the old 'self-evidence' of the axions of reason.

The 'Criterion of Inconceivability' is a touch-stone proposed for ascertaining whether or not a proposition is necessarily true consisting in trying whether or not its denial is inconceivable.
It is taken for granted that a proposition offered as necessarily true will itself be necessary that is it will not only be true under all circumstances but will be an assertion that something would be true under all circumstances whatsoever.
Its denial therefore will assert merely that under some circumstances the proposition would be false. By this denial being inconceivable is meant that it is quite impossible to definitely to realize in imagination a