Spinoza, Monism, and Einstein

"There is a modern equivalent of Spinoza's monism in the view that all transformations in the world are transformations of a single stuff - matter for the Newtonians, energy for the followers of Planck and Einstein. Spinoza himself is sometimes though to be nearer to Einstein, in taking 'motion and rest' as the fundamental variable, and in arguing that 'bodies are distinguished from each other in respect of the motion and rest contained in them' (E 2, 12). However, this 'motion and rest' is not, for Spinoza, an attribute of substance, but an 'infinite mode': in words, something which everywhere inheres in, but is not exhaustive of, the ultimate reality. At the same time, extension (the attribute) can be seen as a 'power to produce motion and rest' (S 120)." Roger Scruton, Spinoza: A Very Short Introduction (New York: Oxford University Press, 2002) p. 54.