Whenever we come upon these matters 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.  If we regard the Spirit of God as the sole fountain of truth, we shall neither reject the truth itself, nor despise it wherever it shall appear, unless we with to dishonor the Spirit of God.

John Calvin, Institutes 2.2.15