Most are, though not all. I'd be grateful if others have recommendations.
* Philip Davis and Reuben Hersh. The Mathematical Experience
"Up till about five years ago, I was a normal mathematician. I
didn't do risky and unorthodox things, like writing a book such as
this."
* Hersh. What Is Mathematics, Really?
In the last chapter, he links up various views of math with right-
and left-wing politics. (In his view, that means elitism and
anti-elitism.)
Incidentally, those who like Martin Gardner (the recreational math
guy) might enjoy Gardner's book _The Whys of a Philosophical
Scrivener_. He rejects anarchism, "Smithianism", etc. I recall
he's into social democracy or something. I think he makes way too
many assumptions, but he's upfront.
Anyway, Gardner negatively reviewed this book and the last one I
mentioned, _The Mathematical Experience_:
http://cs.nyu.edu/pipermail/fom/1997-November/000128.html
* Davis and Hersh. Descartes' Dream: The World According to Mathematics
* 18 Unconventional Essays on the Nature of Mathematics
Haven't read this yet.
* Kolmogorov, Aleksandrov, Lavrent'ev: Mathematics: Its Content, Methods And Meaning
The intro presented a capsule history of math from a 1963's
marxist perspective. Unfortunately, the part about "dialectical
materialism" was excluded from the English version. I heard
Kolmogorov wrote a similar (identical?) paper:
"In 1938, he published a large article, 'Mathematics,' in the first
edition of the Bolshaya Sovyetskaya Entsiklopediya ('Great Soviet
Encyclopaedia'), in which he described the development of
mathematics from ancient to modern times and interpreted it in
terms of dialectical materialism."
* Gian-Carlo Rota. Indiscrete Thoughts
Publishing this book apparently angered some people.
Entertaining and even gossipy book. Hersh (in the foreword)
admitted he didn't grok the occasional mentions of "Husserl's
phenomenology" either.
Tayssir