According to Spinoza, freedom is a concept to be discovered, a path to a better, more powerful life. A freer life. A path that requires us to recognize absolute determinism and the rational causality of things.

He develops his system in the third part of the Ethics. It is the famous "theory of affects".

The principle is that human affects are, says Spinoza, active or passive modifications of the body and thought that influence our power to act, i.e. that is our behavior.

And yet, depending on the affects specific to both human nature and those derived from the outside world, we are perfectly capable of forming true ideas, reasoning and expressing joy.

But we are also capable of forming so-called passive affects, prejudices which then lead us mechanically, "in spite of ourselves" in a way to no longer see or do what our own self-interest requires.

We speak of slavery, or servitude, a state characterized by the inability to control and counteract those passive affects that sometimes lead us to want what we do not do and do what we don't want.

This is what Spinoza says in his Ethics, when he is surprised that "people often see the best, approve of it and do the worst", or that "they fight for their servitude as if they were fighting for their salvation".

Spinoza takes the example of hatred, which he sees as a passive affect, turned towards sadness and born of inadequate ideas, i.e. a partial knowledge of causes, and which he defines as "a sadness that is associated with the idea of an external cause".

In other words, if we hate a foreigner, it's because we associate this foreigner with the idea we have of him, for reasons we don't understand, since he is foreign and different by nature. It's this idea of an external cause - an idea which, moreover, always mechanically motivates the ignorant to speak ill of a concept they don't know.

This is particularly true, by the way, in the field of cryptocurrencies.

Spinoza says if we remove this negative idea of an external cause, not by morality, but by education, by empathy, by reason, notably by focusing in this case on the qualities of this stranger, or in Bitcoin's case, on its practical aspect or usefulness, then the associated feeling of sadness disappears and, automatically, so does hatred.

It's worth remembering that this way of thinking also applies, of course, to active affects, and in particular to love, which is, according to Spinoza, "a joy associated with the idea of an external cause". And if, for example, the external cause of love for a thing or a person disappears or changes over time, the joy associated with it may also disappear, extinguishing the feeling of love. This, when we don't understand it, can make us unhappy and depressed.

But if this so-called theory of affects applies to our "unconscious", this rational way of thinking "in the manner of surveyors" also applies to the fight against all forms of external servitude, whether religious, political or the result of natural phenomena.

This is the example of lightning. Because when lightning strikes and kills innocent people, the ignorant ones will tend to see it as the hand of God, to consider that lightning expresses a moral and finalistic intention. Aids in the 90s or even, more recently, covid have been interpreted by some as divine punishment.

Whereas for Spinoza, of course, all these teleological ideas are merely superstitions, synonymous with ignorance, insofar as in this example the lightning that strikes does nothing, he says, but express the essence of its own nature. Which is to strike. Without, of course, any moral intention to punish or reward anyone.

Thanks to this simple example, we understand that the only solution to protect ourselves from lightning - in other words, to free ourselves from the servitude that its danger has always imposed on us - is not to complain about our bad luck or about a supposed divine injustice, nor is it to put forward the slightest moral argument. No, rather, here again, as with hatred, it’s a matter of reflecting on what we can do from an ethical point of view.

And, in this case, it would be to protect ourselves from lightning by being rational, open to progress, be curious and confident about what science can offer us and, why not, to install a lightning rod.

This is the genius of the Ethics. Spinoza shows us that it is possible to move from voluntary servitude, from a "in spite of ourselves" and a weathervane life of perpetual alienation, to a life lived through the knowledge of affections and determinations.

It's a way of thinking that allows us to dissect human nature in order to see the bright side or the truth in things. To eliminate the reasons for sadness and fear that weigh us down. To be free, in other words, being able to stop obeying sad passions and change our behavior.

And to understand, probably for the first time in the history of philosophy, that you can be lucid and happy.

And that's why Spinozism is often referred to as "the philosophy of joy".