"Read Demosthenes or Cicero, read Plato, Aristotle, or any others of that class; I grant that you will be attracted, delighted, moved, and enraptured by them in a surprising manner; but if, after reading them, you turn to the perusal of the sacred volume, whether you are willing or unwilling, it will affect you so powerfully, it will so penetrate your heart, and impress itself so strongly on your mind, that, compared with its energetic influence, the beauties of rhetoricians and philosophers will almost entirely disappear; so that it is easy to perceive something divine in the sacred Scriptures, which far surpasses the highest attainments and ornaments of human history."
I love that Calvin doesn't say not to read the famous writings of the secular world. He encourages us to read them and to appreciate them. He does, however, point out that we must always be captivated by the scriptures. When we study the Word and understand who God is based on His revelation, we can more clearly see Him in the writings of the secular world.
Who, no matter their field of study, could ever compose poetry, portray emotion in a novel, write of the natural world, or analyze human history without intentionally or unintentionally portraying some element of the divine? We can only come to this appreciation when we are allowing our minds to be transformed (Rom. 12:2) by the scriptures.