“I make my own time. I make my own terms. I cannot see how God or Nature can ever get the start of me.”

Spoken as from a "secular" human being. And that's allowed, but I recommend we be guided by a higher form of concience. If you clash with nature or the God of your understanding, you won't last long.

Its ironic that he said this since he spent so much time at Walden Pond observing creation and how it functioned. Much of his more practical statements seemed to have stemmed from something he had no control over.

Bold indeed. I think it would be an assumption that making one own's time and terms is a clash with God or Nature -- except if God or Nature have designs on us, in which case Liberty is but an illusion. Carpe diem.