a) Sufficient grace, as conceived by the Thomists, is not truly sufficient to enable a man to perform a salutary act, because _ex vi notionis_ it confers merely the power to act, postulating for the act itself a substantially new grace (_gratia efficax_). A grace which requires to be entitatively supplemented by another, in order to enable a man to perform a salutary act, is clearly not sufficient for the performance of that act. “To be truly sufficient for something” and “to require to be complemented by something else” are mutually exclusive notions, and hence “sufficient grace” as conceived by Thomists is in reality insufficient. Many subtle explanations have been devised to obviate this difficulty. Billuart and nearly all the later Thomists say that if any one who has received sufficient grace (in the Thomistic sense of the term) is denied the _gratia efficax_, it must be attributed to a sinful resistance of the will.(724) But this explanation is incompatible with the Thomistic teaching that together with the _gratia sufficiens_ there co-exists in the soul of the sinner an irresistible and inevitable _praemotio physica_ to the entity of sin, with which entity formal sin is inseparably bound up.(725) If this be true, how can the will of man be held responsible so long as God denies him the _gratia ab intrinseco efficax_? Speaking in the abstract, the will may assume one of three distinct attitudes toward sufficient grace. It may consent, it may resist, or it may remain neutral. It cannot consent except with the aid of a predetermining _gratia efficax_, to merit which is beyond its power. If it withstands, it _eo ipso_ renders itself unworthy of the _gratia efficax_. If it takes a neutral attitude, (which may in itself be a sinful act), and awaits efficacious grace, of what use is sufficient grace? To resist sufficient grace involves an abuse of liberty. Now, where does the right use of liberty come in? If coöperation with sufficient grace moves God to bestow the _gratia per se efficax_, as the Thomists contend, then the right use of liberty must lie somewhere between the _gratia sufficiens_ and the _gratia efficax per se_. But there is absolutely no place for it in the Thomistic system. The right use of liberty for the purpose of obtaining efficacious grace is attributable either to grace or to unaided nature. To assert that it is the work of unaided nature would lead to Semipelagianism. To hold that it is owing to grace would be moving in a vicious circle, thus: “Because the will offers no resistance, it is efficaciously moved to perform a salutary act; that it offers no sinful resistance is owing to the fact that it is efficaciously moved to perform a salutary act.”(726)