In this chapter, I'd like to take a look at the history of ideas, and see why Spinozism is considered a true Copernican revolution of ideas.

Thanks to this new way of understanding God, in other words Nature, offered by mathematics, Spinoza (1632-1670) established a profound paradigm shift, with indirect implications for the religious worldview and human's place in it.

Just as Nicolas Copernicus (1473-1543) established that the earth was not the center of the world, and Charles Darwin (1809-1882) showed three centuries later that human beings were not at the center of "life", so Spinoza followed this logic and asserted in his own time that human beings are not the "master of their own house" and that the universe is not made solely for their benefit.

He says that man is not "an empire within an empire" and that, just as the earth is reduced to the status of a mere planet, like all the other planets, the human being is reduced to the status of a mere modes of nature, like all the other finite modes of nature, such as animals, plants and all "existing beings".

Before him, classical Greek philosophy proposed an ordered, hierarchical vision of the universe to explain the world, the cosmos and human experience. Based on mythical narratives, it basically sought to explain the origin of the world, insisting on the harmony of the universe, nature and mankind.

The scholastic cosmology of the Middle Ages, essentially from the 12th century onwards, was an evolution towards more reasoning in order to harmonize reason and faith to explain a universe that was still hierarchical, but which corresponded better to Christian philosophy.

But with the new physics of Copernicus (1473-1543) in the 15th century, cosmology underwent a major turning point in the understanding of the universe, whose geocentric model was thus called into question in favor of the heliocentric system, which paved the way for modern science, notably the new physics and astronomy of Kepler (1571-1630) and Galileo (1564-1642). Then Isaac Newton (1643-1727) and finally Albert Einstein (1879-1955), a committed Spinozist.

But to fully understand Spinozism, we also need to consider the context of René Descartes (1596-1650), the famous French philosopher who preceded Spinoza and of whom he was both a disciple and a great admirer.

Despite the risks and the condemnations of Giordano Bruno (1548-1600) and Galileo, Descartes set out to distinguish "truth from falsehood" and to harmonize theology, philosophy and physics. In his famous Discourse on Method, published in 1637, Descartes argued that reason is the foundation of knowledge, through which human beings can attain freedom.

By explaining the world according to universal laws rather than a nature endowed with moral intentions, he paved the way for determinism, which Spinoza would later according.

But as a Catholic, Descartes nonetheless established a hierarchy between human beings and the other finite mode of nature, and in particular with regard to animal species, what he called "machine animals". And in saying that "there is no soul which, when well guided, cannot acquire absolute power over its actions and passions", Descartes thus claims that human beings have the capacity to start something from nothing, and that man, in his view, "escapes the laws of nature", that he has absolute power over his own actions and grounds his determination solely in himself.

Spinoza knew how to go beyond and surpass this stage and reconcile the existence of God with the demonstration of reason. For him, all fields of human activity depend on the capacities of reason in a perfectly coherent and determined world. But a world in which there is neither contingency nor chance, and in which everything that happens is necessary and the result of a cause, according to the causal link between things. This is the idea of absolute determinism.

And it is in the harshest terms that he finally refutes the Cartesian position, criticizing, for example, the idea that human beings are not subject to the laws of nature like all other animals, and are therefore superior to all other finite modes of nature.

In other words, they are endowed with free will, an illusory belief that is extremely difficult to escape, as Spinoza tells us, and which we shall now discuss.