Curious book, this. When Manent dealt with French and English thinkers, I found his interpretations enlightening. With German thinkers, there was more variation. His take on Kant's moral perspective was very interesting. On the other hand, dealing with Weber primarily from an economic perspective misses, in my opinion, Weber's primary contribution to modern Western thought, which is arguably more historical than economic.
This is not the book to read on the train to work. My copy is full of annotations, and I frequently stopped to check material I wasn't familiar with. For example, it would be over half a century since I read anything about the Peloponnesian War, and a reference to Arginusae had me trawling the web. "Chiasmus" has now been added to the list of words I know the meaning of, but am highly unlikely to use.
Manent believes "in particular possibilities of equality", and sees modern man's continued development as contingent on nature and grace, with the latter the more important of the two. It is unsurprising that a book with this title would end on an organ note in a choir loft. What the reader makes of that will be more down to the reader than to Manent.