Whenever we come upon these matter in secular writers, let that admirable light of truth shining in them teach us that the mind of man, though fallen and perverted from its wholeness, is nevertheless clothed and ornamented with God’s excellent gifts. What then? Shall we deny that the truth shone on 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 they are insane who developed medicine, devoting their labor to our benefit? What shall we say of all the mathematical sciences?? Shall we consider them the ravings of madmen?… Those men whom Scripture calls “natural men” were, indeed, sharp and penetrating in their investigation of earthly things. Let us, accordingly, learn by their example how many gifts the Lord left to human nature even after it was despoiled of its true good.
– John Calvin
as quoted by Horton, Michael; The Gospel Driven Life: Being Good News People in a Bad News World; Baker Books; Grand Rapids, MI; Copyright 2009; page 251-252