What many reviewers say about this book is true: it offers limited details about Kant's philosophy. But there are clearly reasons for that. Author Paul Strathern's ability to discuss the philosophies in detail is severely restricted by the extremely short length of the books, and this becomes more of a problem when he discusses philosophies written in philosophical jargon by intellectuals who didn't write concisely and comprehensibly (and didn't care). Kant and several other major German philosophers, such as Hegel (who also receives a volume in the 90 Minutes series) wrote this way, and how is Strathern supposed to explain poorly written manuals of complex philosophies in ninety minutes? He makes clear that even other philosophers found Kant's writing incomprehensible. He gives one passage from Kant's Critique of Pure Reason
by way of illustration, and it verges on being parody of bad writing:
The apodictical proposition cogitates the assertorical as determined by these very laws of the understanding, consequently affirming as a priori, and in this manner it expresses...
And Critique of Pure Reason is widely considered Kant's masterwork. Kant's unfinished final work in philosophy (Transition from the Metaphysical Foundations of the Natural Sciences to Physics
) is apparently even more incomprehensible, so incomprehensible in fact that, according to Strathern, no other philosophers have ever understood it. In more practical scientific and business fields, this problem is why the professionals have technical writers; unfortunately, philosophers don't have tech writers and probably don't want them. However, Strathern adequately explains key points of Kant's philosophy, such as the categorical imperative everyone hears about.
Strathern mentions something my Philosophy 101 prof didn't see fit to mention about Kant's personal life--the only thing of interest, as he really had no life whatsoever. Throughout his adult life, Kant was absolutely repressed emotionally and sexually. It's not clear how this influenced his philosophy (if at all), but there are subtle hints of his repressed emotions behind the philosophies that interested him, such as the Romanticism of Jean-Jacques Rousseau. Also the fact that he mocked emotional writing like poetic-sounding prose (one of his early works is a satire of it) and advised his students not to read novels (claiming they "fragmented the memory") or listen to music. But Strathern bluntly says "beneath the facade of the prim academic beat the heart of a closet romantic" ; and when I read two other details--that Kant loved attending concerts and, most importantly, that he regularly worshiped in the local church despite his philosophical system denying the existence of God (on the grounds that it's unverifiable)--I made my own conclusion that Strathern doesn't suggest: that Kant was in many ways a blatant (if unintentional) hypocrite.