On March 31, 1596, René Descartes came into the world. Once he entered the intellectual fray, things would never be the same.
Even if you’ve only taken an intro to philosophy course, you probably already have some sense of Descartes’s influence on epistemology and metaphysics. Perhaps his interest for political and moral philosophers isn’t quite as well known, though.
So, let’s celebrate his 421^st birthday with a little list of reasons why lovers of liberty should give René another look.

1. Freedom from Fortune

We all know that Descartes is famous for his method of doubt, but what that method is, exactly, and what motivates Descartes to develop it can be a bit trickier to untangle. But at least one of Descartes’s claims about the method is clear: it will free us from our dependence on fortune.
Without the method, some people found themselves in possession of the knowledge and experience required to develop an understanding of a particular object, idea, or dynamic … and others didn’t.
With the method, we are no longer subject to contingency in the same way. If we commit ourselves to an inquiry, and if we seriously undertake the work of approaching it systematically, we can be confident that we will make progress. Descartes claims to liberate philosophers from indiscriminate fortune or, in other words, to lay the groundwork for an intellectual meritocracy.

2. Freedom of the Will

In the Fourth Meditation, Descartes describes the possibility of avoiding error entirely. His argument rests on the distinctions between understanding, imagination, and will. Imagination concerns mental images, but it is clearly limited. (Just try to form images of a 1000 sided figure and 10,000 sided figure, and see if you can tell the difference between those two images in your head.)
Understanding concerns things that can be rationally apprehended, and Descartes presents it as obviously limited. We can, he says, form the idea of a supremely great and infinite (divine) understanding, and it is immediately clear that human understanding falls far short of it. The will is different, though.
The human will is infinite. It is, he says, in no way inferior to the divine, except insofar as it is constrained by the limits of human imagination and understanding. So, Descartes claims that the way to avoid error is to make sure that the infinite will does not range beyond the boundaries of understanding and imagination.
The implications for this description of the will are, in themselves, fascinating. Human beings have an infinite will, a capacity for freedom of choice that is bounded only by our imagination and our understanding, both of which can be cultivated and expanded. If we are to avoid error, we must rein in the will while we cultivate the understanding and imagination, but as our understanding and imagination grows, so does the scope of our freedom.

Human beings have an infinite will, a capacity for freedom of choice that is bounded only by our imagination and our understanding.”]
Descartes has recontextualized human freedom within completely amoral constraints. If one can understand and/or imagine it, one is free to choose it.

3. Self-Determination

It is easy to make fun of Descartes’s grandiose claim that his method will make us “masters and possessors of nature,” but who can dispute the stunning progress that science and technology has brought to the natural world? We may not be comfortable with mastering and possessing nature, but the obstacles to that today are increasingly more moral than practical.
And, even though contemporary scientific methodology is not exactly Cartesian, it is certainly its heir.
But the ambition to master and possess nature is even less easy to dismiss when we follow the Cartesian turn around to see that it is our own natures that Descartes first helps us to master — our own selves he helps us to possess.

It is our own natures that Descartes first helps us to master — our own selves he helps us to possess.”]
Descartes begins with himself, because self-mastery is the central tenant of any version of his methodology one might discern in his work. And, pushing even more deeply into the preconditions for his project, it is important to note that, for Descartes, such self-determination is possible at all. The claim that we should learn self-mastery is on the surface of Descartes’s writings. The claim that we can is at least as significant, and is fairly easily missed.
But, in the universe of discourse in which Descartes was writing, the claim that human beings could control themselves, direct themselves, perhaps even own (!) themselves was radical, and we should remember to give him credit for that.

4. Freedom of Conscience

In his recent book, Cartesian Psychophysics and the Whole Nature of Man, Richard Hassing argues that the psycho-physical model Descartes presents in the Passions of the Soul laid the groundwork for diagnosing and avoiding the errors of judgment that drive men to conduct religious wars.
So, all those arcane arguments about the pineal gland and its function on the frontier of the spiritual and physical substances of human existence also have a moral and therapeutic aim. As we act, the cavities in our brains change shape. And the more we act in a particular way, the more those cavities change to make those actions frictionless and natural.
Put bluntly, Descartes describes an anatomy that makes independent thought possible. And with it, he offers an alternative to those who believe they must defer to the religion of their fathers, even when it drives them to atrocious behavior.
In the Passions, the chief virtue Descartes describes is Generosity, but this is not Aristotle’s virtue of giving and taking. For Descartes, Generosity is esteeming oneself properly and as highly as possible. One enacts generosity when one realizes that the only thing that we truly possess, as human beings, is the free control of our volitions. The only acts for which we genuinely deserve praise or blame are those where we use our free will well or badly.
Deferring to a group rather than acting on one’s own conscience is never praiseworthy for Descartes. And, the more we do the hard work of acting generously — that is, according to a good use of one’s own free will — the more one’s anatomy will be altered to make such choices and actions more natural. Not only can we distance ourselves from groupthink and appeal to our own conscience to guide our actions, virtue requires that we do.

5. Individual Liberty (for better or worse)

Alexis de Tocqueville opens the second part of Democracy in America with the claim that “America is one of the countries of the world where the precepts of Descartes are least studied and best followed.” What he says he means by that hilarious claim is that 19^th-century Americans share a common philosophical method, even though they don’t know that’s what it is. And, he says, it looks like this:

To escape from the spirit of system, from the yoke of habits, from the maxims of family, from the opinions of class, and, to a certain point, from the prejudices of nation; to take tradition only as information, and present facts only as a useful study for doing otherwise and better; to seek by yourself and in yourself alone the reason for things, to strive toward the result without allowing yourself to be caught up in the means, and to aim for the substance beyond form: such are the principle features that characterize what I will call the philosophical mode of the Americans.”]
What we are now more apt to call radical individualism was, for Tocqueville, Cartesianism, and it worried him. Tocqueville feared that individualism would isolate Americans from one another spiritually, debase our imaginations and our souls. And, as the American spirit spread throughout the world, so would a leveling effect. First Americans, then all “Americanized” peoples would be rendered unable to appreciate refinement, cultivation, ambition. Our unselfconscious, enthusiastic, and contagious Cartesianism would eventually dumb down the world.
Tocqueville had some interesting ideas for how to combat the creep of “soft despotism” in the face of the inevitable rise of individualism. Lovers of liberty have other responses, both to the statement of the problem and to ideas about the conditions under which genius is incubated. So, those of us who have a different perspective on the meaning of individualism for culture may not walk all the way down that road with Tocqueville, but we probably should have something to say about it. And perhaps we can thank Descartes just as legitimately as Tocqueville sought to blame him.