If we regard the Spirit of God as the sole foundation of truth, we shall neither reject the truth itself, nor despise it wherever it shall appear, unless we wish to dishonour the Spirit of God. For by holding the gifts of the Spirit in slight esteem, we contemn and reproach the Spirit himself. What then? Shall we deny that the truth shone upon the ancient jurists who established civic order and discipline with such great equity? Shall we say that the philosophers were blind in their fine observation and artful description of nature? Shall we say that those men were devoid of understanding who conceived the art of disputation and taught us to speak reasonably? Shall we say that they are insane who developed medicine, devoting their labour to our benefit? What shall we say of the mathematical sciences? Shall we consider them the ravings of madmen? No, we cannot read the writings of the ancients on these subjects without great admiration. We marvel at them because we are compelled to recognize how pre-eminent they are. But shall we count anything praiseworthy or noble without recognizing at the same time that it comes from God? Let us be ashamed of such ingratitude, into which not even the pagan poets fell, for they confessed that the gods had invented philosophy, laws and all useful arts. Those men whom Scripture calls 'natural men' were, indeed, sharp and penetrating in their investigation of inferior things. Let us accordingly, learn from their example how many gifts the Lord left to human nature even after it was despoiled of its true good.
John Calvin Institutes of the Christian Religion II.II.15