Spinoza's Ethics, first published in 1677, is a famous attempt to construct a moral philosophy on the basis of a metaphysical theory. Spinoza aims at showing, by rigorous logic, the way in which human beings can cease to be subject to the passions and can be genuinely free. Such freedom consists in activity, and the activity is one of understanding: understanding that one is part of an infinite substance and cannot exist in isolation from it. This substance, which Spinoza call's 'God', is an all-inclusive and impersonal being, which exists and acts of necessity. The Ethics is one of the most notoriously difficult of philosophical works, yet it continues to exercise a peculiar fascination. This new edition is specifically designed to throw light on the problems which surround its interpretation, and consider Spinoza's philosophy in the context of his life and work. Professor Parkinson has provided a new introduction, explanatory notes and a comprehensive index, and Andrew Boyle's original Everyman translation has also here been radically revised.