In logic, the converse of a categorical or implicational statement is the result of reversing its two parts. For the implication P → Q, the converse is Q → P. For the categorical proposition All S is P, the converse is All P is S. In neither case does the converse necessarily follow from the original statement. The categorical converse of a statement is contrasted with the contrapositive and the obverse.
If S is a statement of the form P implies Q (P → Q), then the converse of S is the statement Q implies P (Q → P). In general, the verity of S says nothing about the verity of its converse, unless the antecedent P and the consequent Q are logically equivalent.
For example, consider the true statement “If I am a human, then I am mortal.” The converse of that statement is “If I am mortal, then I am a human,” which is not necessarily true.
On the other hand, the converse of a statement with mutually inclusive terms remains true, given the truth of the original proposition. Thus, the…