Calvin says, as Aristotle and numerous others before him, that all men have a natural desire to know the truth that continues to function in some manner after the fall. Passages such as these are crucial in understanding Calvin’s theology of original sin. Man’s natural gifts remain after the fall but they are wounded by the removal of grace and the inherent habit of sin. The understanding also remains but with an added corruption.
When we so condemn human understanding for its perpetual blindness as to leave it no perception of any object whatever, we not only go against God’s Word, but also run counter to the experience of common sense. For we see implanted in human nature some sort of desire to search out the truth to which man would not at all aspire if he had not already savored it. Human understanding then possesses some power of perception, since it is by nature captivated by love of truth. The lack of this endowment in brute animals proves their nature gross and irrational. Yet this longing for truth, such as it is, languishes before it enters upon its race because it soon falls into vanity. Indeed, mans mind, because of its dullness, cannot hold to the right path, but wanders through various errors and stumbles repeatedly, as if it were groping in darkness, until it strays away and finally disappears. Thus it betrays how incapable it is of seeking and finding truth. Institutes, II.2.12.
By the phrase “finally disappears” Calvin is not saying that no unbeliever can know anything of the truth. Rather, he is explaining in metaphorical terms the habit or wound of ignorance that has come upon human understanding due to original sin. Further on he again affirms that the understanding has not lost all of its good functions.
Yet its [the understanding’s] efforts do not always become so worthless as to have no effect, especially when it turns its attention to things below. On the contrary, it is intelligent enough to taste something of things above, although it is more careless about investigating these. Ibid., II.2.14.
I think it is often difficult for us to look beyond some of Calvin’s less philosophical rhetoric concerning the damage of original sin. For example, he states a bit earlier in his Institutes that “that part in which the dignity and excellence of the soul are most conspicuous, has not only been wounded, but so corrupted, that mere cure is not sufficient. There must be a new nature.” Ibid., II.2.9.
We must not think that Calvin is always speaking in terms of Aristotelian philosophy. Rather, in these passage he is discussing the inability of man, through the use of his corrupted faculties, to render himself complete and righteous before God. In this sense he follows in the tradition that descends from St. Paul himself, who says that men are “by nature the children of wrath” (Eph. 2:3) and “All have turned aside; together they have become worthless; no one does good not even one.” (Rom. 3:12)
However, Calvin does speak in terms of Aristotelian anthropology when he distinguishes between the essential nature of man that remains after the fall and the corrupt habit that is added afterward. In this vain he admits than all men still have a natural desire for the truth and may even partially fulfill this desire through the knowledge of natural things and even some things supernatural.