Considering the way the word “socialist” has been thrown around lately, it’s helpful to do a definition check. G.A. Cohen, a University of Oxford professor who died last August, sums it all up in an informative and thought-provoking little essay. Princeton has published a new, pocket-sized hardcover edition that’s both timely and useful. Cohen uses the example of a camping trip to illustrate how society functions, and then expands that illustration to explain how socialism works. He dismantles the idea that human selfishness is the bar to a working form of socialism, acknowledges the failures of central planning and posits a democratic socialism that uses the market rather than attempting to control it. While Cohen admits that all market systems are predatory, that’s no reason to simply surrender. Logically, concisely and deliberatively, he offers some good reasons to seek an alternative.