obvertend

Thus, if _No S is not-P_ be given us to recover the obvertend or to find the corresponding affirmative; the proposition being formally negative, we apply the rule for obverting negatives: 'Remove the negative sign, and for the predicate substitute its contradictory.'

Logic Deductive and Inductive Carveth Read 1889

Again, having obtained the obverse of a given proposition, it may be desirable to recover the obvertend; or it may at any time be requisite to change a given infinite proposition into the corresponding direct affirmative or negative; and in such cases the process is still obversion.

Logic Deductive and Inductive Carveth Read 1889

Similarly, to obtain the obvertend of _All S is not-P_, apply the rule for obverting Affirmatives; and this yields _No S is P_.

Logic Deductive and Inductive Carveth Read 1889

The given proposition is called the 'obvertend,' and the inference from it the

Logic Deductive and Inductive Carveth Read 1889

Thus the obvertend being -- _Some philosophers are consistent reasoners_, the obverse will be -- _Some philosophers are not inconsistent reasoners_.

Logic Deductive and Inductive Carveth Read 1889