I'm reading John Frame's Apologetics to the Glory of God, wherein he mentions that God gave Adam special (verbal) revelation PRE-FALL, which, Frame says, was a gracious condescension on God's part, given that even the pre-fall man's finite mind may not have been able to comprehend God's speaking and directing him through the Book of Nature. He emphasizes that Nature is just as much the Word of God as Scripture, and elsewhere affirms its perspicuity. My question is a minor quibble, but one which - upon clarification, could really help me understand more about how to deal with Natural Revelation - especially in terms of it's Romans 1 implications with regard to man's suppression of the truth in unrighteousness. How is it that Frame can say that Adam, pre-fall even, may have not been able to comprehend Natural Revelation due to his finite mind, and yet maintain the perspicuity of NR? Does perspicuity differ from, say, understandability? Can we say that NR is CLEAR, while also granting that it may be unable to teach us and direct us without the aid of Special Revelation, even, say, before we take into account our sinful propensity to supress the truth??? Thanks for the help with this matter.