Few philosophers have been so mythologised as the 17th century Jew, Baruch Spinoza. Legends abound regarding his life, thought and character. He has been claimed as hero and as villain by both secular and ecclesiastical authorities. During his life he was widely attacked for his 'blasphemous' and 'heretical' opinions on God, the bible, and religion, even suffering one of the most vitriolic cherem (excommunication) ever issued by the Amsterdam Portuguese-Jewish community. But after his death he was appropriated by others who believed that within his complex writings could be found a deeply religious instinct. To German romantics like the poet Novalis, he was "a God intoxicated man", while Goethe called him simply theissimus, 'most theistic'. So what was Spinoza's attitude to God? Certainly no one who read his work thoroughly could argue that he held a traditional theistic conception of a divine being, the providential God of Abraham, Isaac and Jacob. In the Ethics, his philosophical masterpiece, Spinoza says that God is 'immanent' in nature, not some supernatural entity beyond the world. But does this mean that we can describe him as a pantheist, as someone who believes that God is revealed in every aspect of the natural world that lies around us? This was certainly a popular interpretation.

The philosopher John Toland, in the early 18th century, insisted that the terms 'Spinozism' and 'pantheism' are synonymous – Toland says that "Moses was, to be sure, a Pantheist, or, if you please, in more current terms, a Spinosist" – while Spinoza's pantheism was taken for granted by Moses Mendelssohn, Gotthold Lessing and Friedrich Jacobi, in their famous Pantheismusstreit of 1785. More recently, this interpretation also appears in both the scholarly literature and popular representations of Spinoza's thought. In the recently published Cambridge Dictionary of Philosophy we read that "Spinoza is the most distinguished pantheist in Western philosophy".

But the problem with calling Spinoza a 'pantheist' is that pantheism is still a kind of theism. For while atheists and pantheists might agree that ontologically there is nothing else to the world but nature, they would part company when the pantheist goes on to insist that the identification of God with nature makes it appropriate to hold the religious psychological attitudes demanded by theism. In effect, the pantheist who asserts that 'God is nature' is divinising nature and claiming that the world is in some sense holy or sacred, and that therefore one's attitude towards nature must be akin to a religious experience. Nature is properly regarded with worshipful awe, perhaps even fear and dread.

Atheists disagree. While they too may (at least in terminology if not in substance) identify God with the natural world, in so doing they are not divinising nature but naturalising God. They see no justification for regarding nature or the world with anything like worshipful awe. They may, of course, still fear nature and its destructive forces, or admire its awesome beauty. But this is very different from religious fear and awe in the face of the inscrutable and ineffable divine, and very different from the spirit of Spinoza's philosophy.

Spinoza does not believe that worshipful awe is an appropriate attitude to take before God or nature. There is nothing holy or sacred about nature, and it is certainly not the object of a religious experience. Instead, one should strive to understand God or nature, with the kind of adequate or clear and distinct intellectual knowledge that reveals nature's most important truths and shows how everything depends essentially and existentially on higher natural causes. The key to discovering and experiencing God/nature, for Spinoza, is philosophy and science, not religious awe and worshipful submission. The latter give rise only to superstitious behaviour and subservience to ecclesiastic authorities; the former leads to enlightenment, freedom and true blessedness (i.e. peace of mind).

To be sure, Spinoza is at times capable of language that seems deeply religious. In the Ethics, he says that "we feel and know by experience that we are eternal", and that virtue and perfection are accompanied by a "love of God (amor Dei)". But such phrases are not to be given their traditional religious meaning. Spinoza's naturalist and rationalist project demands that we provide these notions with a proper intellectualist interpretation. Thus, the love of God is simply an awareness of the ultimate natural cause of the joy that accompanies the improvement in one's condition that the highest knowledge brings; to love God is nothing but to understand nature. And the eternity in which one participates is represented solely by the knowledge of eternal truths that makes up a part of the rational person's mind.

There is no place in Spinoza's system for a sense of mystery in the face of nature. Such an attitude is to be dispelled by the intelligibility of things. Religious wonder is bred by ignorance, he believes. Spinoza contrasts the person who "is eager, like an educated man, to understand natural things" with the person who "wonders at them, like a fool". For Spinoza, anyone who would approach nature with the kind of worshipful awe usually demanded by the religious attitude represents the latter.

By definition, and in substance, pantheism is not atheism. And Spinoza is an atheist.

Steven Nadler, Professor of Philosophy at University of Wisconsin-Madison, is the author of Spinoza's Heresy: Immortality and the Jewish mind (OUP)