identity of indiscernibles

Also known as: Leibniz’s Law

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identity of indiscernibles, principle enunciated by G.W. Leibniz that denies the possibility of two objects being numerically distinct while sharing all their properties in common. More formally, the principle states that if x is not identical to y, then there is some property P such that P holds of x and does not hold of y, or that P holds of y and does not hold of x. Equivalently, if x and y share all...