Looking back on his life, the elderly Albert Einstein located his most significant existential turning point in a single moment of wonderment when he was a small boy. But what is wonderment, exactly, and what gives it the power to possess us so completely as to recalibrate our very being?

That is what René Descartes (March 31, 1596–February 11, 1650) examines in several passages from The Passions of the Soul (public library) — his final published work, which gave us the influential French philosopher and mathematician’s ideas about the cure for indecision, the relationship between fear and hope, and how we acquire nobility of soul.

Descartes writes:

When our first encounter with some object takes us by surprise, and we judge it to be new, or very different from what we have previously experienced or from what we expected it to be, this causes us to wonder at it and be astonished. And because this can happen before we have any knowledge of whether the thing is beneficial to us or not, it seems to me that wonderment is the first passion of all. And it has no contrary, because, if the object that presents itself has nothing in itself to surprise us, we are not moved by it in any way and we consider it without any passion.

He offers a definition of wonderment kindred to Diane Ackerman’s notion of “deep play” and examines how it works its magic on the mind:

In wonderment, the soul is suddenly taken by surprise, which causes it to consider attentively the objects that it finds rare and extraordinary. Thus, it is caused first and foremost by the impression formed in the brain which represents the object as rare, and consequently worthy of close consideration; and then by the movement of the spirits, which are disposed by this impression, first, to rush towards the part of the brain where it is located in order to reinforce it and preserve it there, and, secondly, to flow from there into the muscles that serve to keep the sense-organs in the same state as they are now, so as to keep the original impression going (supposing it was formed by them in the first place).

Four centuries before the pioneering Harvard psychologist Jerome Bruner defined creativity as the art of “effective surprise,” Descartes writes:

The impact of wonderment can be very powerful, because of the surprise involved: that is, the sudden and unexpected occurrence of the impression that alters the movement of the spirits. This surprise is so characteristic of wonderment that, when it is encountered in other passions, in almost all of which it is commonly found, its effect being to reinforce them, this is because they contain an admixture of wonderment. And its impact results from two things: first, the novelty of the experience; and, secondly, the fact that the movement it causes is at its most powerful at the beginning. For this kind of movement certainly has more effect than those that are weak at the beginning and intensify only gradually, so that they can be easily diverted. It is also certain that sense-objects new in our experience affect the brain in parts in which it is unaccustomed to be affected; and since these parts are softer or less firm than those hardened by frequent stimulation, the movements produced there have all the more impact. This will not be so difficult to believe if we reflect that the same reason applies to the soles of our feet, which feel a significant impact when we walk, on account of the weight of the body they are supporting, and yet, since they are accustomed to it, we hardly notice this; whereas if they are tickled, the far milder and more gentle touching is almost unbearable, simply because we are not used to it.

But wonderment, Descartes cautions, belongs to a continuum of experience which, like all continua, can grow perilous in its extreme end. He describes the paralytic effects of excessive wonderment:

The whole body remains motionless as a statue, and we can perceive nothing of the object but the aspect of it first presented to us, so that we can gain no more detailed knowledge of it. This is what is commonly called being astonished; and astonishment is an excess of wonderment that can only ever be bad.

Descartes suggests that where astonishment is dumbfounding and bereft of utility, wonderment causes the tentacles of our curiosity to reach toward its object and thus expands the mind into previously unconquered territories:

We can say of wonderment that its particular utility is to enable us to learn and retain in our memory things of which we were formerly unaware. For we wonder at only what appears to us rare and extraordinary; and nothing can so appear to us except when we were previously unaware of it, or it differs from what we knew; for it is on account of this difference that we call something extraordinary. Now, even when something previously unknown presents itself for the first time to our understanding or our senses, we do not necessarily retain it in our memory for all that, unless our idea of it is fortified in our brain by some passion, or else by the application of our intellect, when determined by the will to concentrate on and think hard about the object. And the other passions can serve to enable us to notice what appears good or evil, but for those that just appear rare we have only wonderment. And so we see that those without any natural inclination to this passion are ordinarily very ignorant.

Half a millennium before the exploitive and mind-hollowing astonishment mongering of the Buzzfeed era, Descartes issues a darkly cautionary caveat:

But excessive wonderment, and astonishment at the sight of things that deserve little or no consideration, occurs far more frequently than its contrary. And this excess can entirely suppress or distort the use of reason…. For it is easy to make up for the lack of it by careful reflection and attention, to which our will can always compel our understanding when we judge that the thing we have encountered is worth the trouble; but to eliminate the tendency to excessive wonderment, there is no other remedy than to acquire a knowledge of many things, and to habituate oneself to thinking about whatever may seem most rare and strange…. blind curiosity can become a lifelong disease: the curiosity, that is, of people who seek out what is rare only to marvel at it, not to understand it; for they gradually become so prone to wonderment that the most trivial things are no less capable of engaging their attention than those that are most worth investigating.

Complement this particular portion of The Passions of the Soul with Diane Ackerman’s poetic invitation to wonderment and Rachel Carson on science and wonder, then revisit Descartes on the key to a wakeful mind and his twelve timeless tenets of critical thinking.