Strathern generally fits more of the history – sometimes more focused on the individual, sometimes on the era – than the philosophic contributions. This satisfies one of the things I want to know at the expense of the other, but I will freely admit that most of the men (I have seen one woman covered in his Authors in 90 Minutes series) have ideas that cannot be properly defined in less words than they themselves used. Giving a nutshell – really more of a sketch – of the contributions is (in some cases) enough for the casual reader, and by always including biographical information about the philosopher in question, there is not only a context for the thought but a humanization of the thinkers.
If one has read either History of the Concept of Time (1925) – translated by Dr. Theodore Kisiel, who I met while at NIU – or its logical extension, Being and Time (1927), then one knows that its is almost impossible to follow Heidegger's line of thought without an expert on call for help. Strathern fully embraces the difficulty with Heidegger's repurposing of language; how could he not? But he does get around to giving the reader a rough concept of how phenomenology influenced the children's classic The Neverending Story (1979).
In a short book, it is nearly impossible to do more than state that Kant destroyed the notion of space and time as we understand them (and clearly, we have chosen not to go his route since we still understand them in a practical sense) without giving the reasoning as to how Kant came to his conclusion and why he may be right. (Kant argues that time and space are both categories of perception and have meaning only to the extent they allow us to order our understanding and experiences. Moreover, as we cannot be the things we perceive, we can never have real knowledge of them, but only that of which we perceive – we cannot reason things as we do ideas. Thus our knowledge of the world is only related to the ultimate truth of the world in as much as our perceptions are flawless and sync up with proper reasoning.)
Strathern does do a good job of both praising Kant as quite possibly the brightest mind since St. Augustine of Aquinas (and until Wittgenstein) and showing where his limitations were obvious. This is no piece of idol worship, but Strathern does seem to hold Kant in higher esteem than most of the other figures in the series (at least as far as I've read). Unfortunately, he does not seem especially well versed in Kantian philosophy (and Strathern seems to believe that current philosophers no longer advocate any kind of metaphysical thinking, which is not what I experienced in my time studying philosophy).
There is a better book by Roger Scruton – Kant: A Very Short Introduction (2001) – and I suggest that one instead. Not as easy a read, but more rewarding.
Rousseau's Dog: Two Great Thinkers at War in the Age of Enlightenment (2007). Strathern does give a good general sense to the man who advocated for liberty, but not so much his paranoia or his constant battles against the system he exploited to (farcically) live life on his own terms. Not a bad read by any stretch of the imagination, but this is not where one should end when reading about Rousseau.