Internal sanctification may be defined as a permanent, vital union with God, by which the soul becomes righteous and holy in His sight and obtains a claim to Heaven. That this is also a function of sanctifying grace appears from those Scriptural texts which treat of the positive element of justification.(963) With this doctrine Tradition is in perfect accord, and consequently the Fathers of Trent were right in teaching as they did, in fact they could not have taught otherwise.(964) b) While all Catholic theologians admit the incompatibility of grace and sin in the same subject, they differ as to the kind and degree of opposition existing between the two. Some hold that this opposition is purely moral, others that it is physical, again others that it is metaphysical. α) Nominalists(965) and Scotists(966) before the Tridentine decision maintained that the distinction between sanctifying grace and (original or mortal) sin is based on a free decree of the Almighty, and therefore purely moral. God, they held, by a _favor externus superadditus_, externally supplies what sanctifying grace internally lacks, just as a government’s stamp raises the value of a coin beyond the intrinsic worth of the bullion. Followed to its legitimate conclusions, this shallow theory means that sanctifying grace is of itself insufficient to wipe out sin, and that, but for the superadded divine favor, grace and sin might co-exist in the soul. This is tantamount to saying that justification requires a twofold formal cause, _viz._: sanctifying grace and a _favor Dei superadditus_,—which runs counter to the teaching of Trent. Henno tries to escape this objection by explaining that the _favor Dei acceptans_ appertains not to the formal but merely to the efficient cause of justification. But this contention is manifestly untenable. Sanctifying grace is either able to wipe out sin, or it is unable: if it is unable to produce this effect, the _favor Dei acceptans_ must be part of the _causa formalis_ of justification, and then, in Henno’s hypothesis, we should have a _duplex causa formalis_, which contradicts the Tridentine decree. If, on the other hand, sanctifying grace is able to wipe out sin without any _favor superadditus_, then the Scotistic theory has no _raison d’être_.