The topic sentence is found at the beginning of the paragraph because the topic senence has the summary of what the paragraph eill be talking about and so it intorduces what you will be reading in the following paragraph.
I haven't read it, so I cannot be completely sure, but based on the title of this work, I am assuming that the major theme of "Life without Principle" is freedom. You are not constrained by principle to do whatever you want, and that is the definition of freedom.
