I've also completed chapter 5 today (book 1 of institutes). Wonderful quotes from Virgil and Augustine. Calvin has a pretty stark review of the nature of man, in this chapter, though I agree with your analysis that this is balanced  with the light of God's revelation, of Himself, in everything created. I keep finding the person of God in Calvin’s arguments and an understanding of God’s personal intervention in both the world and our life to “direct” our thoughts toward a true knowledge of both His person and His purpose for our lives. I don’t believe Calvin has us there however I feel he’s heading toward the principles of Hebrews chapter 11, verse 1: “ Faith is the assurance of things hoped for, the conviction of things not seen.” Our faith is in the divinity and resurrection of Jesus Christ, our savior. I took a look at the Greek and “assurance” is actually a noun which describes the foundation of a structure, like a building. The word “conviction” is a noun which defines a ‘legal document; like the deed to a property or a marriage certificate. From chapter 5, I feel Calvin is saying our faith, which leads to a true knowledge of God, is supported by: the awareness all men have of Him, His revelation in all things great and small, and divinely inspired scripture.  I feel there are a few more points to define in this analysis of the revelation of God’s true self to man however I don’t want to get ahead of where we are in Calvin’s writings; what a wonderful mind he had.