In this final chapter on the new Copernican vision of ideas offered by Spinozism, we turn finally to the third illusion presented by Spinoza (1632-1677) in his work, the Ethics.

This illusion is directly linked to the first two, the illusion of free will and the illusion of finality.

It's about theological illusion.

The point is this: As long as humans are ignorant, "of both things and themselves", as Spinoza tells us, as long as they believe in their illusory freedom, they will take their imagination for understanding, i.e. they will always consider themselves capable of thinking and understanding the nature of things, when in reality they are only imagining, inventing and projecting what is useful to them. According to their desires.

This is why humans believe that if natural means exist and are useful, such as teeth for eating or eyes for seeing, it's because they were logically created by a "director of nature". In other words, an intentional, anthropomorphic God to whom human intentions are attributed.

In other words, a white-bearded old man hidden behind a cloud, who is credited with creating all things in nature as a means to our end, because he loves us, and protects us as we honor and worship him.

This is the first stage of theological illusion.

But despite our pride in believing ourselves to be above Nature, and in imagining that we can start something from nothing, in reality we are always subject to conditions of existence that indicate that, in the end, we won't really be able to "get away with it", as philosophy professor Gilles Deleuze (1925-1995) put it. We are mortal, like all animals, but we know it.

Believing or imagining the opposite in order to reassure ourselves is the reason why we are perpetually tossed back and forth between fear and hope, like two opposing and inseparable poles between a feeling of security and a feeling of panic, since fear is always linked to the hope of better days.

That there is no fear without hope, nor hope without fear, and that he who fears always hopes to escape what he fears, while he who hopes always fears that what he hopes for will not happen.

And since "we are disposed to believe easily what we hope for", says Spinoza in his Ethics, it's when we face external causes or events that would be harmful to us, contrary to any idea of utility, that the second stage of this so-called theological illusion is expressed, characterized by beliefs from which superstitious sentiment arises.

In other words, "the infamous" according to Voltaire (1694-1778), for whom superstition is never born of reason, and it always corresponds to an irrational or unfounded belief, opposed to any form of rationality by attributing to objects or actions powers or spiritual potency that they don't have.

Under the guise of relieving us, of allowing us to imagine a better world, superstition actually locks us into our own illusions and lies. In servitudes from which we'll have a hard time extricating ourselves.

This is what the German, English and French Enlightenment defended from the 18th century onwards, asserting that superstition simply prevents men from becoming adults, not only by limiting the exercise of reason, but also, and above all, by giving rise to intolerance, which is the best instrument for establishing the domination of a power. Whether political or religious.

And this is what Spinoza demonstrates again in his Theologico Political Treatise, which we've already touched on. In this essay, he writes that "the great secret of the monarchical regime, and its major interest, is to deceive people, and to disguise with the name of religion the fear which must control them". This is why tyrants, dictators or revolutionaries, who are always people driven by the desire to do good for others, often, if not always, fall into the trap of doing the opposite of their principles in order to achieve them.

But the novelty that Spinoza brings to the TTP, and which makes him in a way the father of secularism, is to consider that while it is essential to fight superstition and the call to violence that freedom paradoxically allows, the fact is that it is in the stat's interest to protect the right to believe and the freedom to think.

For as soon as ideas exist and are expressed privately, they will inevitably spread throughout society, and neither prohibition nor censorship can ever prevent their spread. Ideas, whether true or false, good or bad, will circulate in any case, and banning them can only lead, in the long term, to revolt and the overthrow of the state in the name of freedom.

In other words, the state would actually have far more to fear from censorship or suppression of freedom of expression than from maintaining it, and it is therefore, says Spinoza, in its interest to let individuals exercise their natural right to think and express themselves.

For Spinoza, a democratic state that allows freedom of thought is therefore the best guarantee that people will live in peace, and that, thanks to the exercise of reason, they will not only be free to think and act, but will also be able to understand the servitudes that constrain them in order to extricate themselves from them.