Baruch Spinoza (24 November 1632 – 21 February 1677) was one of the greatest of the early modern rationalists. In his political philosophy, together with Locke, he laid the foundations of the Enlightenment. In his metaphysics he opposed Descartes’ dualism of mind and body, maintaining instead that thought and extension are attributes or mode of a single substance, namely God. The universe itself is a mode of God. Spinoza thereby argued for the identity of mind and body. He is considered by many to be an atheist, by others a pantheist.
Spinoza argued that all change takes place by necessity, proceeding according to a universal deterministic law. Free will is an illusion, arising in humans because whilst we are often aware of our appetites, we do not generally understand why we want and act as we do. We may however form more ‘adequate’ ideas of our appetites and affections, and in this sense become the adequate cause of our effects. And whilst or indeed because everything that happens, happens necessarily, we are the more free when we understand this, and are less in ignorance of our choices and of the reasons why we act as we do.
Like Hume, however, Spinoza did not think it possible to live by reason alone. An appetite can only be opposed by another appetite. The objective, rather, is to understand our appetites, whereby they become ‘active’ rather than ‘passive’ affections. The highest virtue, according to Spinoza, was the intellectual love of Nature.
Spinoza was born of Saphardic Portuguese Jews in Amsterdam. There he attended the Keter Torah Yeshiva of the Amsterdam congregation, and later, under private study with the former Jesuit and free-thinker Francis van den Enden he studied Latin and read widely in modern philosophy, including the writings of Descartes. He worked throughout his life as an optician, but through his writings was censored by the Jewish community in Amsterdam, from which he was effectively excommunicated; his writings were also banned by the Pope. His greatest work, the Ethics, was published posthumously.
Through his skills as a lens-maker Spinoza was also actively involved in telescope design and construction, and was held in high regard by Christian Huygens. He corresponded widely; he met with Leibniz at the Hague, on whom he was a significant influence. He died at the age of 44, atheist, pantheist, and secular Jew.