DE Weekly: Spinoza, Rationalism, & Determinism
Below is an archived email originally sent on January 12, 2026.
Spinoza, Rationalism, & Determinism
“There can be no hope without fear, and no fear without hope.” These words belong to Baruch Spinoza, a philosopher of the Dutch Golden Age in the seventeenth century. What Spinoza meant by this is that, as we project our future, our hope for something carries with it inherently the risk of losing it. Such is the fundamental nature of our will. But why is our will like this?
Today, we’ll discuss Spinoza’s unique brand of rationalism and determinism, as well as his personal spirituality which informed his philosophy.
Before we are able to decipher the meaning of that quote, however, we must first diagnose the roots of Spinoza’s philosophy.
Spinoza is best known for his Ethics, wherein he studied how to live a moral life, like most philosophers have.
In his studies of ethics he had an existential realization that, in our ordinary waking lives, much of what we engage in on a daily basis is entirely pointless; the things we strive for and after are largely meaningless and futile.
What is the meaning of seeking pleasure, riches, and worldly honors if they ultimately lead to dissatisfaction and vanish? This was a core existential concern of his.
He further argued that we also often act against our best interests, and do so consciously. In other words, we usually see the good but choose the bad anyway.
We see that living with and for others is the more fulfilling path, but still go after riches and pleasure.
Is this how things have to be? Is this really the natural order of things? Well, yes, Spinoza argues––but it doesn’t have to stay that way.
A sort of liberation is available to us when we embrace reality for what it is, in a way that allows us to become the best version of ourselves possible, through living authentically.
There are two factors relevant to Spinoza’s philosophy which inform this line of thinking: his aforementioned rationalism and determinism.
Spinoza’s rationalism prioritizes reason and judgment over perception and superstition about the nature of the world.
His determinism supposes the free will all of us have is actually an illusion; for Spinoza, the laws of the universe are beyond our comprehension, yet ruled by a cause-and-effect relationship that dictates our lives.
Where do those universal laws come from? Spinoza recognized they come from God, of course. But it’s important to mention that Spinoza’s God is vastly different than the traditional Christian understanding of God.
Spinoza did not see God and His creation as two separate things, but as one and the same. His substance monism held that there is only one substance––God and nature––and that everything else is just a modification of that one substance.
His influence is clear today when we look at philosophies such as Panpsychism, which I have written about previously.
For Spinoza, God is not outside the universe. He is the universe. As a result, He is not an involved God; his God has no plans for us, no designs. Everything that happens, then, happens according to the nature of the universe.
In essence, Spinoza’s God is a rational, infinite system which encapsulates everything. Perhaps most important in this system is his conclusion that, as humans, we have no free will at all. We are simply modifications of existence.
Without free will, what is our purpose?
For Spinoza, like the existentialists deduced, it is to live an active life. However, unlike the existentialists, he argues we don’t do this by striving to create our own meaning. Because, in a world with no free will, we have no will to create meaning.
This is where Spinoza differentiates from the existentialists most notably. You see, for him, the world is not absurd. It is entirely rational, entirely sensical.
Instead of escaping the absurdity then (for it does not exist), we must strive instead to understand the cause of our affections through reason and act accordingly.
If we have a rational understanding of our determined existence, then we can affirm the necessity of all things in the world, including our Self.
Once we understand our Self and our own existence––that we are a modification of the universe and exist rationally––we can control our passions and emotions and act authentically within the deterministic structure of reality we find ourselves in.
If we were to read Spinoza through an existential lens, we could determine a few things.
First, we have no free will and thus no radical freedom. Instead, our essence is simply a part of nature. Therefore, we do not have to invent a meaning for our life, as it already exists.
Second, we need not search for a reason to live. We are necessary parts of an eternal whole, and accepting our place as a single substance within God/nature/the universe justifies our living.
In confronting our existential dread in such a manner, Spinoza urges us to live a life of active accordance with nature, not one that seeks to break outside of it and bend the rules.
The result: total alignment with the rational order of the universe, and an intellectual love of God.
“If the way I have shown to lead these things now seems very hard, still, it can be found. And of course, what is found so rarely must be hard. For if salvation were at hand, and could be found without great effort, how could nearly everyone neglect it? But all things excellent are as difficult as they are rare.” –– Baruch Spinoza, Ethics
Thanks for reading.
Sincerely,
Brandon J. Seltenrich
P.S.––
This year, I’d like to write about some different philosophers outside of existentialism to paint a better picture of how they differ in their thinking. I’d love to know what you thought about this one.
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