A third school of theologians tries to solve the difficulty by adding to the natural operation of the intellect and the will some accidental supernatural _modus_. There are several such _modi_, which, though inhering in nature and really distinct therefrom, depend solely on the Holy Ghost, and consequently transcend the natural powers of man, _e.g._ the duration or intensity of a salutary act. This theory at first blush appears more plausible than the other two, but it cannot be squared with the teaching of Tradition. In the first place, the duration or intensity of a salutary act cannot affect its essence or nature. Then again, every such accidental supernatural _modus_ is produced either by grace alone, or by grace working conjointly with free-will. In the former hypothesis it would be useless, because it would not render the free salutary act, as such, supernatural; in the latter case it could do no more than aid the will to do what is morally impossible, whereas every salutary act is in matter of fact a physical impossibility, that is, impossible to unaided nature.(293) There remains a fourth explanation, which ascribes to every salutary act an ontological, substantial, intrinsic _supernaturalitas_, whereby it is elevated to a higher and essentially different plane of being and operation. This theory is convincingly set forth by Suarez in his treatise on the Necessity of Grace.(294) It may be asked: If the salutary acts which we perform are supernatural in substance, why are we not conscious of the fact? The answer is not far to seek. Philosophical analysis shows that the intrinsic nature of our psychic operations is no more a subject of immediate consciousness than the substance of the soul itself. Consequently, sanctifying grace cannot reveal its presence through our inner consciousness. Having no intuitive knowledge of our own Ego, we are compelled to specify the different acts of the soul by means of their respective objects and their various tendencies (cognition, volition). To our consciousness the supernatural love of God does not present itself as essentially different from the natural.(295) Article 3. The Necessity Of Actual Grace For The States Of Unbelief, Mortal Sin, And Justification Every adult man, viewed in his relation to actual grace, is in one of three distinct states: (1) The state of unbelief (_status infidelitatis_), which may be either negative, as in the case of heathens, or positive, as in the case of apostates and formal heretics; (2) The state of mortal sin (_status peccati mortalis_), when the sinner has already received, or not yet lost, the grace of faith, which is the beginning of justification; (3) The state of justification itself (_status iustitiae sive gratiae sanctificantis_), in which much remains yet to be done to attain eternal happiness. The question we have now to consider is: Does man need actual grace in every one of these three states, and if so, to what extent?