The doctrine of _Mental Reservation_ seems to me to differ from that of _Equivocation_ only in this, that Equivocation implies the use of words which have a two-fold meaning in themselves, _apart from_ special circumstances, and are therefore _logical_ equivoques. Thus to the question: “_What do people think of me?_” one might diplomatically reply: “_Oh! they think a great deal!_” which leaves it undetermined whether the thinking be of a favourable or unfavourable character. But more commonly words, apart from special circumstances, have one definite meaning, _e.gr._, “_Yes_” or “_No_.” When Sir Walter Scott denied, as he himself tells us, the authorship of “_Waverley_” with a plain simple “_No_,” he was guilty of no logical Equivocation: but the circumstance that it was generally known that the author intended to preserve anonymity gave his answer the signification, “_Mind your own business._” This is what I should call a _moral_ equivoque. The Scholastics call it _broad mental reservation_ (_restrictio late mentalis_). The origin of this terminology seems to me to lie in a bit of purism. Some moralists were not content with merely _moral_ equivoques: they appear to insist on the junction with them of _logical_ Equivocation; and so they would have directed the equivocator to _restrict_ (and so double) the meaning of a word in his own mind. Thus to Sir Walter they would have said: “Don’t say ‘_No_’ simply, but add in your own head, ‘_as far as the public is concerned_,’” or something similar. When this addition could not be conjectured by the hearer, it received the name of _pure mental reservation_ (_restrictio pure_ [or _stricte_] _mentalis_): as when one might say “_John is not here_” (meaning in his mind “not on the exact spot where the speaker stood”), though John was a yard off all the time. Such a position has not found favour in the body of Catholic moralists. They regard it as not only a useless proceeding, but as one which, although intended out of respect for truth, is liable, from its purely subjective character, to easy abuse. But when objective circumstances (as in the case of Sir Walter) enable the hearer to guess at the double meaning and to suspend his judgment, then we have a case of _broad_ mental reservation: for it is writ large in social convention that, where a momentous secret exists, a negative answer carries with it the limitation (restriction, reservation), “_secrets apart_.” I trust I have made it sufficiently clear that the doctrine of Equivocation, properly understood, has been devised in the interests of Veracity. That we may find in some writers, whether St. Alphonsus de Liguori or Professor Paulsen, particular applications in which we do not concur, surely does not affect the validity of the principle.