The first one

Hello Rabbi!
I finished the third conversation (the physical-theological evidence) in the book “The First Testimony,” and I saw that the fourth conversation talks “about inferential and revealing arguments.”
My question is, is the fourth conversation necessary to complete the structure of the physico-theological argument as presented in the third conversation, or is it a different approach to the same topic?
thanks!
(By the way, I thank you very much for this book in general. I am grateful that there are people like you)