Being and Worth extends recent depth-realist philosophy to the question of values. It argues that beings both in the natural and human worlds have worth in themselves, whether we recognise it or not. This view is defended through and account of the human mind as essentially concerned with that of which it is independent. The book builds on Roy Bhaskar's proof tha facts can entail values, and it aims to repeat in the realm of ethics his argument that experiment and change in science show that there is a depth-dimension of real structures in nature and society. This it does by a partial defence and immanent critique of Spinoza's philosophy of mind and ethics. It argues that reason is a principle in humankind which is not human-centred, but takes us out of ouselves to value beings for what they are. This leads in the end to an ethics which owes more to St Augustine than to Spinoza, in that it rests on the idea that 'being as being is good', though not all beings are equally good. Several obvious objections to this view are answered. Conclusions follow both for environmental ethics - that natural beings should be valued for themselves, not just for their use to us - and for justice in the human world, based on the idea that humans are unique and equal in respect of 'having a life to live'.