Review: HEIDEGGER IN 90 MINUTES by Paul Strathern

Martin Heidegger was a German philosopher of the 20th century. He was a student of Hegel, and in turn was pretty much the Third Reich's pet philosopher. 

Paul Strathern is a British author who has written extensively, especially about science and philosophy, including about 40000 of these books. He writes them in a dry, ironic tone that I like.

I can't think of a quicker way to learn about the various philosophers and their thought. If you have any interest in philosophy at all, I highly recommend this and the other books in the sense.