Doubt. Philosophers distinguish between two kinds of doubt, real and methodical. Real doubt is the kind where the mind remains suspended between two contradictory propositions, without having any reason that would cause it to tilt one way more than another. Methodical doubt is the kind where the mind suspends its assent to truths that it does not really doubt, in order to gather proofs that render these truths invulnerable to all possible attacks.

Descartes, naturally brilliant and insightful and aware of the emptiness of Scholastic philosophy, resolved to develop for himself a completely new philosophy. As he was in Germany in his winter quarters without anything to occupy him, he spent several months reviewing the knowledge he had acquired, either in his studies or through voyages; he found so much obscurity and uncertainty in what he had previously studied that the idea came to him to tear down this unsatisfactory edifice and to rebuild, as one might say, from the ground up, while establishing more order and connections in his principles.

He began by setting aside revealed truths because he thought, as he said, that in order to successfully examine them, it was necessary to have extraordinary help from heaven and to be more than human. Therefore, the first maxim of behavior he adopted was to obey the laws and customs of his country, while steadfastly retaining the religion in which, by God's grace, he had been instructed since childhood. In all other matters the most moderate opinions would be the guiding principle of his behavior. He believed that it was wise to provisionally adopt this rule because the successive search for the truths he wanted to know could be very long; a code of behavior was necessary because human activity cannot be postponed. This consideration caused him to add a second maxim to the first, which was to be as firm and as resolute in his behavior as possible and to follow steadfastly the most uncertain opinions, once he had chosen a particular course, just as he would have had those opinions been highly certain. His third maxim was to try always to govern himself rather than fortune and to change his desires rather than the order of the world.

Having assured himself of these maxims and having put them aside with the truths of faith, which were always first among his beliefs, Descartes judged that he could freely go about divesting himself of the rest of his opinions. And in this he was right; but he was mistaken when he believed that calling them into question was sufficient for this end. Doubting whether 2 + 2 are 4 or whether man is a reasonable animal implies having ideas of 2, of 4, of man, of animal, of reasonable. Doubt allows ideas to remain as they are; thus, given that our errors have their origin in our ill-formed ideas, doubt cannot prevent those errors. Doubt can, for a time, cause us to suspend our judgment; but in the end we will find our way out of uncertainty only by consulting the ideas that doubt has not destroyed; and consequently, if those ideas are vague and poorly specified, they will lead us astray as before. Descartes' doubt is thus useless: each of us can personally experience how impractical it is; for, if one compares familiar and well-defined ideas, it is not possible to doubt the relations that exist among them: relations, for example, such as those between numbers. If one can doubt everything, it is only by way of a vague and indeterminate doubt, which applies to nothing at all in particular.

If Descartes had not been disposed in favor of innate ideas, he would have seen that the only way to establish a new store of knowledge was to destroy ideas themselves and then start again from their origins, that is to say, from sense impressions. Our greatest debt to this philosopher is that he left us the account of his intellectual journey. Instead of directly attacking the Scholastic philosophers, he describes the time when he had the same prejudices as they. He does not conceal in the least the obstacles that he had to overcome in order to rid himself of the Scholastic philosophy; he provides the rules of a method far more simple than any that had been used before him, allows us a glimpse of the discoveries that he believes he has made, and in this way prepares our minds to receive the new opinions he proposed to establish. I believe that this way of proceeding played a major role in the revolution begun by this philosopher.

The doubt introduced by Descartes is quite different from that in which the Skeptics lock themselves. The Skeptics, in doubting everything, were determined to remain forever in their doubt, whereas Descartes used doubt as a starting point for the sole purpose of establishing his knowledge on a firmer foundation. In Aristotle's philosophy, according to Descartes' disciples, one doubts nothing, one accounts for everything, and, nevertheless, nothing is explained except by barbaric and unintelligible terms and by obscure and unclear ideas. Descartes, on the other hand, even if he causes you to forget what you already know, compensates you richly with the sublime knowledge to which he leads you by degrees; this is why his disciples apply to him what Horace said about Homer:

[“Not smoke from brightness, but from smoke light he plans to give, so that thereafter he might bring forth beautiful marvels.” [1]]

It is necessary to state here that there is considerable difference between doubting and doubting. We doubt for numerous reasons: anger and brutality, blindness and malice, and, finally, fantasy, and because we want to doubt; but we doubt also because of prudence and distrust, because of wisdom, and because of intellectual shrewdness. Academics and Atheists doubt in the first way described; true Philosophers doubt in the second way. The first doubt is one of darkness, which does not lead to light, but which moves rather always in the opposite direction. The second kind of doubt is born of light, and it helps, in turn, to produce light. This is the doubt, one can say, that is the first step toward the truth.

It is more difficult to doubt than one imagines. One perceptive writer has observed that those individuals who possess fiery temperaments and fervent imaginations do not easily accept the indifference characteristic of the Skeptic; they prefer to make a risky choice rather than do nothing, to err rather than live in uncertainty: whether they lack confidence in their arms or whether they fear the water's depth, we see them always hanging from branches whose weakness they acknowledge and to which they prefer to cling rather than leaping into the rushing stream. They affirm everything, although they haven't examined anything carefully; they doubt nothing because they have neither the patience nor the courage: subject to glimmers that convince them, if by chance they encounter the truth, it’s not at all the result of a gradual process, but all at once, in the manner of a revelation. They are among Dogmatists what the illuminated are among the religiously devout. Members of this anxious species cannot conceive how one can combine intellectual tranquility with indecision.

One must not confuse doubt with ignorance. Doubt presupposes a deep and disinterested analysis; the person who doubts because he does not recognize the reasons that validate the truth is merely ignorant.

While it happens that a well-formed mind may reject dogmatic assertions in matters where the evidence for and against is nearly equal, it would nevertheless be contrary to reason to suspend one's judgment in those matters where the strongest evidence reigns. Such doubt is impossible; it occasions harmful consequences for society and closes all paths that could lead to the truth.

Nothing is more evident than that this kind of doubt is impossible; because, in order to reach such doubt, one would have to have reasons equally for and against regarding all kinds of matters. So, I ask: is such a thing possible? Who ever seriously doubted whether there is an earth, a sun, and a moon and whether the whole is bigger than its parts? Can our individual awareness of our existence be obscured by subtle and specious reasons? We can cause our mouth to express our doubt of these things, because we can lie; but we cannot force the same assent to occur in our mind. Thus, Pyrrhonism is not a sect of people who are persuaded by what they say; it is rather a sect of liars: therefore it happens that they often contradict themselves when they express their opinion, as their heart is in contradiction with their tongue, as one can see with Montaigne, who tried to renew this philosophy during the last century. [2]

For, after having said that the Academics were different from the Pyrrhonians, because the Academics admitted that some things are more plausible than others, something that the Pyrrhonians did not want to admit, Montaigne supports the Pyrrhonians in these terms: "the opinion," he states, “of the Pyrrhonians is bolder and at the same time more plausible.” There are thus some things that are more plausible than others; and he wasn't just trying to make a clever remark; these are the words he used spontaneously without thinking and which are instinctive and which untruthful opinions cannot stifle.

Moreover, doesn't every act performed by a Pyrrhonian refute their philosophy? For a Pyrrhonian is a person who, according to his principles, is obliged to universally doubt everything, who is not even supposed to know whether some things are more probable than others; a Pyrrhonian ought not know whether it is more advantageous to follow nature's impressions or to reject them. If a Pyrrhonian respected his principles, he would have to remain in a state of perpetual apathy, without drinking, without eating, without seeing his friends, without respecting laws, habits, and customs, becoming, in a word, petrified and immobile like a statue. If a rabid dog attacks him, he should not take even one step to escape; if his house is on the point of collapsing and of burying him in the ruins, he should not go outside; if he is weak from hunger or thirst, he should not eat or drink. Why? Because we never do anything except as a result of some internal judgment by which we affirm that there is some danger, which we should try to avoid and that in order to avoid such danger, we should do such and such a thing. If we don’t, it’s because the mind remains in a state of inaction, without reaching a decision. Fortunately for Pyrrhonians, instinct compensates for, and with interest, what is lacking in their conviction, or, rather, it serves as a corrective to the extravagance of their doubt.

But, they will say, if danger seems likely, this is sufficient for us to feel obliged to avoid it; we do not deny appearances; we simply assert that we do not know that things really are in effect as they appear to us to be. But this reply is only a vain subterfuge; it will not allow them to escape the objection raised against them. I accept that danger may appear to them to be likely, but by what reason do they attempt to avoid it? Perhaps the danger they fear is actually something extremely good for them. Moreover, I would really like to know if they have an idea of danger, doubt, probability; if they do, then they know something, that is to say, that there are dangers, doubts, probabilities: this then is for them a first sign of truth. One of their constant reflexes is that they should live like other people and not call attention to themselves, that they should follow their instincts and that they should adapt their behavior to laws and customs. But where did they acquire all of these principles? Skeptical in their manner of thinking, how can they be dogmatic in their way of behaving? This one point that they concede becomes a stumbling block upon which all of their vain abstractions are shattered.

Nonetheless, Pyrrho sometimes behaved in accordance with his philosophy. Persuaded that nothing is certain, he took his indifference in some matters as far as his philosophy allowed him. It is said that he liked nothing and that nothing ever made him angry and that when he spoke, he cared little whether one listened to him; and even if his audience departed, he continued speaking. If all men were like this, what would happen to society? Nothing is more contrary to society than this kind of doubt. In effect it destroys and overturns all laws, whether natural, divine or human; it opens a vast space for all kinds of disorder and authorizes the greatest crimes. From this principle that one must doubt everything, it becomes uncertain whether there is a supreme being, whether there is a religion, whether there is a belief system that we are required to obey. With this principle as a starting point—that one must doubt everything—it follows that all actions become indistinguishable and that the sacred boundaries established between good and evil, between vice and virtue, are overturned.

Now, who doesn't see how pernicious these consequences are for society? These effects can be seen by considering Pyrrho himself who, when his teacher Anaxarchus had fallen into an abyss, went on about his business without making any effort to rescue him; Anaxarchus, who professed the same principles, far from rebuking Pyrrho, seemed to be grateful to him, thus sacrificing the resentment he should have felt for his disciple to the honor of his philosophy.

This doubt is contrary to the search for the truth because, once accepted, it closes all roads to the truth, and one cannot have assurance regarding any truth rule: nothing seems certain enough not to require proof; thus in this absurd philosophical system an infinite regression would be necessary in order to find a principle on which one could establish one's belief.

I will go even further: this doubt is excessive and unworthy of a man who thinks; whoever accepted this philosophy in practice would certainly reveal signs of the most amazing madness: for such a man would doubt whether one must eat in order to live, whether one should flee when threatened by an immediate danger: he will be unable to distinguish between the merits of conflicting choices. This doubt is completely unworthy of a man who thinks; it reduces him below the level of animals; for how is man different from animals? Isn't the difference this: that in addition to receiving sense impressions from external objects—which is perhaps common to animals also—man possesses faculties for judging and willing: this is the most noble function of his reason, the most noble operation of his mind; but Skepticism renders these two faculties useless. In a Skeptical world, man will not judge at all; indeed, not judging becomes a law for him, and the Skeptics call this epoche. So, if a man suspends his judgment, it's clear that his will has no work to do and becomes inactive to the point where it seems sluggish or numb; for the will cannot choose anything that the mind has not previously discerned to be good or bad; however, a mind steeped in Pyrrhonian principles is plunged into darkness. But it can judge, they will say, that one thing appears to be more pleasing than others. That should not really be in their philosophy; nevertheless, in conceding this point to them, one does not also concede to them that there is a sufficient reason to decide to pursue such an object; this reason can only come from one’s firm conviction that one should pursue those objects that are most pleasing.

What conclusions should one draw from all of this? Perhaps this: that an authentic and perfect Pyrrhonian is, intellectually, a monster that one should pity. Uncompromising Pyrrhonism is reason's folly and the most ridiculous product of the human mind. One could reasonably doubt whether there are any true Skeptics; regardless of their efforts to make others believe in their philosophy, there are moments, and these moments are frequent, when they are not able to suspend their judgment; they become like other men. They constantly catch themselves off-guard, as certain as the proudest Dogmatists. Take Pyrrho for instance, who became angry with his sister one day, because he had been obliged to buy things she needed in order to offer a sacrifice. Someone admonished him that his anger was incompatible with the apathy he professed. Do you think, he answered, that I want to practice this virtue for a woman? Do not take this to mean that he was not renouncing love; this was not at all what he meant. He meant that all kinds of things were not worthy of the practice of his philosophy, which was to avoid becoming angry. See Pyrrhonism and Skeptic. [3]

Notes

1. [Brenda Fineberg, Knox College, translated this passage from Horace's Ars Poetica; her translation is used here with permission.]

2. [Diderot refers here to Montaigne's attempt to revive Skeptical philosophy "during the last century." This lapsus is explained as follows: the passage that begins, “Thus, Pyrrhonism is not a sect of people” and continues through “and which untruthful opinions cannot stifle” is a nearly word for word quotation from Antoine Arnauld's and Pierre Nicole’s Logique de Port-Royal (“Premier Discours”). Arnauld and Nicole, of course, were writing in the 17th century. For them, but not for Diderot, Montaigne was “the last century.”]

3. [I am grateful to Laurence Devillairs, Collège de France, and my colleagues Caesar Akuetey and Jerry Miner, Knox College, for their intelligent and useful recommendations regarding style and interpretation.]