Determinism is the doctrine that the world's condition at any given time is a consequence of its condition at some prior time. The world is predictable only to the extent that it is deterministic, but even a strictly deterministic world cannot possibly be entirely predictable. The reasons for this are stated in this fast-paced, tightly argued monograph, as are the reasons why, contrary to what is generally assumed, it can in fact be established with reasonable certainty that the world is at least approximately deterministic. The difference between indeterminism and randomness is also discussed, and some important but oft-overlooked consequences of this distinction are identified.