But such a distinctive endowment may be the the curse of man if he fails to use it rightly. Like Job, Dante insists that life is a warfare. Victory is possible only by the right exercise of the will enlightened by God. Defeat is sure if the will embraces sin. To Dante sin is not a mere vulgarity or the violation of a social convention or "a soft infirmity of the blood." "Very hateful to his fervid heart and sincere mind," says James Russell Lowell, "would have been the modern theory which deals with sin as involuntary error." To Dante sin is the greatest evil of the world--not only because it is the source of all other evils, but because it is at once the denaturing of man--the damned are characterized as "the woeful people who have lost the good of the understanding" (Inf., III, 18), and it is also a defiance of God. Sin, then, is Atheism--a rejection of God, with a conviction that pleasure or happiness can be attained outside of God, independent of God and in opposition to God. Apart from the inspired writers of Holy Writ it is doubtful whether any other writer ever had such an awful sense of sin and such a vivid vision of sin and its consequences as Dante has given to the world in a picture which has burned terror into the thought of man. To show us that life is a warfare against sin, Dante gives us several striking pictures of temptation and heavenly deliverance from evil. At the very beginning of the Divine Comedy, we see his ascent to the mountain of the Lord barred by Lust, Pride and Avarice represented by a leopard, a lion, and a wolf. He is victorious over those enemies of his salvation because Reason (Virgil) and Beatrice (Revelation) come to his aid. Temptation is also exhibited in Ante-Purgatorio and that is the more remarkable because both as a theologian and a poet Dante holds that the present life is the end of man's probation and that as a consequence, temptation is not to be encountered in the next life. Why it is put forth in Ante-Purgatorio is explained by the theory that our poet here nods, that he means, not the actual Purgatory of disembodied spirits, but moral Purgatory, _i.e._, the present life wherein man, striving upward, is attacked by temptation to keep him from the end for which God created him. Showing temptation in Ante-Purgatorio, the poet gives us a picture of souls protected by two angels against the serpent. Here is the scene: