Introduction to Spinoza’s Ethics (from Prof. Stuart Hampshire’s Introduction to Prof. Edwin Curley’s translation of Benedict de Spinoza’s Ethics, 1994, London 1996)

Spinoza begins his Ethics with arguments to prove that there must be a single self-subsistent substance, to be identified as ‘Deus sive Natura’, ‘God or Nature’, which is the cause, directly or indirectly, of all things, and which is self-created. This statement is a denial of the possibility of a transcendent creator, distinct from his creation, and a denial of the first principles of Judaism and of Christianity. God must be immanent in the natural order, the creator in its creation, if we are to avoid the incoherence of thinking of two substances in reality: a creator distinct from his creation. There could not have been an act of creation, as Jews and Christians claim that there has been; this would imply that God had reason to choose to create the actual world rather than other possible worlds. But what reason could there be other than the creator’s nature which made the actual world the only possible world? We must think of the natural order as the unfolding of God’s nature in accordance with eternal laws which consitute his essential nature. The origin of things is not to be found in an act of will, but rather in the rational order which constitutes God or Nature. These arguments for God’s immanence undermine the orthodox tradition of Western morality and metaphysics, and they remove the need for any intermediary between God and man in the form of a Church and of a priesthood. We do not need any privileged revelation of God’s intentions and we must not apply to God any part of the vocabulary that is applicable to finite human minds. […]

Spinoza was always denounced during his life, and for a century afterwards, as not only an atheist, but also as a materialist and a determinist: that is, he claimed that all things, including persons, are determined in their actions by the laws of physics. The phrase ‘Deus sive Natura’, ‘God or Nature’, gives a sense in which he was an atheist, but he was a materialist with a difference and also a determinist with a difference. Human beings do not have supernatural souls and their processes of thought are inseparably linked to bodily processes. This entails that, for every change in a human mind, which can be explained in psychological terms, there must be a replica in the body which is a change to be explained in the terms of physical laws. This seems a form of materialism. Our mental powers and our physical powers are indissolubly linked – but we can learn to understand the natural order, at least in part, sub specie aeternitatis, under its aspect as an eternal framework and system of natural laws. Our knowledge of the intellectual order of things will always be fragmentary, because our powers of mind are limited and the intellectual order is unlimited and infinite. This is materialism with a difference, because God or Nature is as much an intelligible system of thought as a system of material objects. Spinoza’s so-called determinism is the belief that all behaviour, whether of human beings or of other natural creatures, is to be explained by causes, but by causes of two contrasting kinds: causes that are eternally valid as explanations of their effects, and causes that are valid as explanations at a particular time and in particular circumstances. Any living thing’s desire to avoid pain and death is an example of a cause of the first kind: my desire to avoid my particular neighbour provides a cause of my behaviour which explains it within the common order of causes in nature and sub specie durationis. The first kind of explanation is a complete explanation and the statement of it is a necessary truth. The second kind of explanation is incomplete, because the chains of causes stretch back in time without limit and stopping-point in the common order of nature. Our knowledge of this second kind of cause must always be comparatively unreliable because imperfect. There is an absolute distinction in Spinoza’s philosophy between understanding some part of the intellectual order of things, which is knowledge of eternal truths, and the contrasting knowledge of things as they exist at a particular time in the common order of nature. Mathematics and the fundamental laws of physics (laws of motion) and laws of psychology (laws of thoughts) belong to the first category; the useful truths of medicine and of statecraft belong to the second category.