Blaise Pascal

French mathematician, physicist, inventor, writer, and Christian philosopher (1623–1662)

Blaise Pascal (19 June 162319 August 1662) was a French mathematician, logician, physicist and theologian.

To make light of philosophy is to be a true philosopher.
Note: All quotes from the Pensées are on that page.


Our reason is always disappointed by the inconstancy of appearances.
If we look at our work immediately after completing it, we are still too involved; if too long afterwards, we cannot pick up the thread again.
  • For as old age is that period of life most remote from infancy, who does not see that old age in this universal man ought not to be sought in the times nearest his birth, but in those most remote from it?
    • Preface to the Treatise on Vacuum (c.1651)
  • Je n'ai fait celle-ci plus longue que parce que je n'ai pas eu le loisir de la faire plus courte.
  • People almost invariably arrive at their beliefs not on the basis of proof but on the basis of what they find attractive.
    • De l'Art de persuader ["On the Art of Persuasion"], written 1658; published posthumously.
  • Mahomet established a religion by putting his enemies to death; Jesus Christ, by commanding his followers to lay down their own lives.
  • FEU. Dieu d'Abraham, Dieu d'Isaac, Dieu de Jacob, non des philosophes et savants. Certitude. Certitude. Sentiment. Joie. Paix.
    • FIRE. God of Abraham, God of Isaac, God of Jacob, not of the philosophers and scholars. Certainty. Certainty. Feeling. Joy. Peace.
    • Note on a parchment stitched to the lining of Pascal's coat, found by a servant shortly after his death, as quoted in Burkitt Speculum religionis (1929), p. 150
  • When I consider the short duration of my life, swallowed up in the eternity before and after, the small space which I fill, or even can see, engulfed in the infinite immensity of spaces whereof I know nothing, and which know nothing of me, I am terrified, and wonder that I am here rather than there, for there is no reason why here rather than there, or now rather than then. Who has set me here? By whose order and design have this place and time been destined for me?—Memoria hospitis unius diei prætereuntis.
    It is not well to be too much at liberty. It is not well to have all we want.
    How many kingdoms know nothing of us!
    The eternal silence of these infinite spaces alarms me.

Discourses on the Condition of the Great

  • In order to enter into a real knowledge of your condition, consider it in this image: A man was cast by a tempest upon an unknown island, the inhabitants of which were in trouble to find their king, who was lost; and having a strong resemblance both in form and face to this king, he was taken for him, and acknowledged in this capacity by all the people.
  • Thus he had a double thought: the one by which he acted as king, the other by which he recognized his true state, and that it was accident alone that had placed him in his present condition.
  • Do not imagine that it is less an accident by which you find yourself master of the wealth which you possess, than that by which this man found himself king.
  • If it had pleased them [the legislators] to order that this wealth, after having been possessed by fathers during their life, should return to the republic after their death, you would have no reason to complain of it.
  • The whole title by which you possess your property, is not a title of nature but of a human institution.
  • This right which you have, is not founded any more than his upon any quality or any merit in yourself which renders you worthy of it. Your soul and your body are, of themselves, indifferent to the state of boatman or that of duke; and there is no natural bond that attaches them to one condition rather than to another.
  • If you act externally with men in conformity with your rank, you should recognize, by a more secret but truer thought, that you have nothing naturally superior to them.
  • If the public thought elevates you above the generality of men, let the other humble you, and hold you in a perfect equality with all mankind, for this is your natural condition.
  • Do not mistake yourself by believing that your being has something in it more exalted than that of others.
  • What would you say of that man who was made king by the error of the people, if he had so far forgotten his natural condition as to imagine that this kingdom was due to him, that he deserved it, and that it belonged to him of right? You would marvel at his stupidity and folly. But is there less in the people of rank who live in so strange a forgetfulness of their natural condition?
  • All the excesses, all the violence, and all the vanity of great men, come from the fact that they know not what they are: it being difficult for those who regard themselves at heart as equal with all men... For this it is necessary for one to forget himself, and to believe that he has some real excellence above them, in which consists this illusion that I am endeavoring to discover to you.
  • If, being duke and peer, you would not be contented with my standing uncovered before you, but should also wish that I should esteem you, I should ask you to show me the qualities that merit my esteem. If you did this, you would gain it, and I could not refuse it to you with justice; but if you did not do it, you would be unjust to demand it of me; and assuredly you would not succeed, were you the greatest prince in the world.
  • What is it, in your opinion, to be a great nobleman? It is to be master of several objects that men covet, and thus to be able to satisfy the wants and the desires of many. It is these wants and these desires that attract them towards you, and that make them submit to you: were it not for these, they would not even look at you; but they hope, by these services... to obtain from you some part of the good which they desire, and of which they see that you have the disposal.
  • God is surrounded with people full of love who demand of him the benefits of love which are in his power: thus he is properly the king of love.
  • You are in the same manner surrounded with a small circle of persons... full of desire. They demand of you the benefits of desire... You are therefore properly the king of desire. ...equal in this to the greatest kings of the earth... It is desire that constitutes their power; that is, the possession of things that men covet.
  • It is not your strength and your natural power that subjects all these people to you. Do not pretend then to rule them by force or to treat them with harshness. Satisfy their reasonable desires; alleviate their necessities; let your pleasure consist in being beneficent; advance them as much as you can, and you will act like the true king of desire.
  • There are some men who expose themselves to damnation so foolishly by avarice, by brutality, by debauches, by violence, by excesses, by blasphemies! is always a great folly for a man to expose himself to damnation... He must despise desire and its kingdom, and aspire to that kingdom of love in which all the subjects breathe nothing but love, and desire nothing but the benefits of love.

Conversation on Epictetus and Montaigne

  • In reading this author [ Montaigne ] and comparing him with Epictetus, I have found that they are assuredly the two greatest defenders of the two most celebrated sects of the world, and the only ones conformable to reason, since we can only follow one of these two roads, namely: either that there is a God, and then we place in him the sovereign good; or that he is uncertain, and that then the true good is also uncertain, since he is incapable of it.
  • If it is pleasing to observe in nature her desire to paint God in all his works, in which we see some traces of him because they are his images, how much more just is it to consider in the productions of minds the efforts which they make to imitate the essential truth, even in shunning it, and to remark wherein they attain it and wherein they wander from it, as I have endeavored to do in this study.
  • The source of the errors of these two sects, is in not having known that the state of man at the present time differs from that of his creation; so that the one, remarking some traces of his first greatness and being ignorant of his corruption, has treated nature as sound and without need of redemption, which leads him to the height of pride; whilst the other, feeling the present wretchedness and being ignorant of the original dignity, treats nature as necessarily infirm and irreparable, which precipitates it into despair of arriving at real good, and thence into extreme laxity.
  • These two states which it is necessary to know together in order to see the whole truth, being known separately, lead necessarily to one of these two vices, pride or indolence, in which all men are invariably led before grace, since if they do not remain in their disorders through laxity, they forsake them through vanity, so true is that which you have just repeated to me from St. Augustine, and which I find to a great extent; for in fact homage is rendered to them in many ways.
  • One, knowing the duties of man and being ignorant of his impotence, is lost in presumption, and that the other, knowing the impotence and being ignorant of the duty, falls into laxity; whence it seems that since the one leads to truth, the other to error, there would be formed from their alliance a perfect system of morals. But instead of this peace, nothing but war and a general ruin would result from their union; for the one establishing certainty, the other doubt, the one the greatness of man, the other his weakness, they would destroy the truths as well as the falsehoods of each other. So that they cannot subsist alone because of their defects, nor unite because of their opposition, and thus they break and destroy each other to give place to the truth of the Gospel. This it is that harmonizes the contrarieties by a wholly divine act, and uniting all that is true and expelling all that is false, thus makes of them a truly celestial wisdom in which those opposites accord that were incompatible in human doctrines.
  • These philosophers of the world place contrarieties in the same subject; for the one attributed greatness to nature and the other weakness to this same nature, which could not subsist; whilst faith teaches us to place them in different subjects: all that is infirm belonging to nature, all that is powerful belonging to grace. Such is the marvelous and novel union which God alone could teach, and which he alone could make, and which is only a type and an effect of the ineffable union of two natures in the single person of a Man-God.

On the Spirit of Geometry

  • C'est une maladie naturelle à l'homme de croire qu'il possède la vérité directement…
    • It is a natural illness of man to think that he possesses the truth directly…
      • Section I
    • Variant translation: It is man's natural sickness to believe that he possesses the Truth.

The Art of Persuasion

As translated by O. W. Wright Full text online at Bartleby
  • No one is ignorant that there are two avenues by which opinions are received into the soul, which are its two principal powers: the understanding and the will.
  • All men are almost led to believe not of proof, but by attraction. This way is base, ignoble, and irrelevant; every one therefore disavows it. Each one professes to believe and even to love nothing but what he knows to be worthy of belief and love.
  • I do not speak here of divine truths... because they are infinitely superior to nature: God alone can place them in the soul... I know that he has desired that they should enter from the heart into the mind, and not from the mind into the heart, to humiliate that proud power of reasoning that pretends to the right to be the judge of the things that the will chooses; and to cure this infirm will which is wholly corrupted by its filthy attachments.
  • Whilst in speaking of human things, we say that it is necessary to know them before we can love them...the saints on the contrary say in speaking of divine things that it is necessary to love them in order to know them, and that we only enter truth through charity.
  • They [men] have corrupted this [God's supernatural] order by making profane things what they should make of holy things, because in fact, we believe scarcely any thing except which pleases us.
  • God only pours out his light into the mind after having subdued the rebellion of the will by an altogether heavenly gentleness which charms and wins it.
  • Of the truths within our reach... the mind and the heart are as doors by which they are received into the soul, but... few enter by the mind, whilst they are brought in crowds by the rash caprices of the will, without the council of reason.
  • Several particular maxims... are as powerful, although false, in carrying away belief, as those the most true.
  • As soon as the soul has been made to perceive that a thing can conduct it to that which it loves supremely, it must inevitably embrace it with joy.
  • A doubtful balance is made between truth and pleasure, and... the knowledge of one and the feeling of the other stir up a combat the success of which is very uncertain, since, in order to judge of it, it would be necessary to know all that passes in the innermost spirit of the man, of which man himself is scarcely ever conscious.
  • It is necessary to have regard to the person whom we wish to persuade, of whom we must know the mind and the heart, what principles he acknowledges, what things he loves; and then observe in the thing in question what affinity it has with the acknowledged principles, or with the objects so delightful by the pleasure which they give him.
  • The art of persuasion consists as much in that of pleasing as in that of convincing, so much more are men governed by caprice than by reason!
  • The principles of pleasure are not firm and stable. They are different in all mankind, and variable in every particular with such a diversity that there is no man more different from another than from himself at different times.
  • There are hardly any truths upon which we always remain agreed, and still fewer objects of pleasure which we do not change every hour, I do not know whether there is a means of giving fixed rules for adapting discourse to the inconstancy of our caprices.
  • This art, which I call the art of persuading, and which, properly speaking, is simply the process of perfect methodical proofs, consists of three essential parts: of defining the terms of which we should avail ourselves by clear definitions, of proposing principles of evident axioms to prove the thing in question; and of always mentally substituting in the demonstrations the definition in the place of the thing defined.
  • If we do not secure the foundation, we cannot secure the edifice.
  • A few rules include all that is necessary for the perfection of the definitions, the axioms, and the demonstrations, and consequently of the entire method of the geometrical proofs of the art of persuading.
  • Rules for Definitions. I. Not to undertake to define any of the things so well known of themselves that the clearer terms cannot be had to explain them. II. Not to leave any terms that are at all obscure or ambiguous without definition. III. Not to employ in the definition of terms any words but such as are perfectly known or already explained.
  • Rules for Axioms. I. Not to omit any necessary principle without asking whether it is admittied, however clear and evident it may be. II. Not to demand, in axioms, any but things that are perfectly evident in themselves.
  • Rules for Demonstrations. I. Not to undertake to demonstrate any thing that is so evident of itself that nothing can be given that is clearer to prove it. II. To prove all propositions at all obscure, and to employ in their proof only very evident maxims or propositions already admitted or demonstrated. III. To always mentally substitute definitions in the place of things defined, in order not to be misled by the ambiguity of terms which have been restricted by definitions.
  • These eight rules [above] contain all the precepts for solid and immutable proofs.
  • Five [of the above] rules are of absolute necessity, and cannot be dispensed with without essential defect and often without error.
  • Rules necessary for definitions. Not to leave any terms at all obscure or ambiguous without definition; Not to employ in definitions any but terms perfectly known or already explained.
  • Rules necessary for axioms. Not to demand in axioms any but things perfectly evident.
  • Rules necessary for demonstrations. To prove all propositions, and to employ nothing for their proof but axioms fully evident of themselves, or propositions already demonstrated or admitted; Never to take advantage of the ambiguity of terms by failing mentally to substitute definitions that restrict or explain them.
  • These five rules [above] form all that is necessary to render proofs convincing, immutable, and to say all, geometrical; and the eight rules together render them even more perfect.
  • It is necessary to show that there is nothing so little known [as the above rules], nothing more difficult to practice, or nothing more useful and universal.
  • As to the objection that these rules are common in the world, that it is necessary to define every thing and to prove every thing, and that logicians themselves have placed them among their art, I would that the thing were true and that it were so well known... But so little is this the case, that, geometricians alone excepted, who are so few in number that they are a single in a whole nation and long periods of time, we see no others that know it.
  • If they have entered into the spirit if these rules, and if the rules have made sufficient impression on them to become rooted and established in their minds, they will feel how much difference there is between what is said here and what a few logicians may perhaps have written by chance approximating to it in a few passages of their works.
  • All who say the same things do not possess them in the same manner; and hence the incomparable author of the Art of Conversation pauses with so much care to make it understood that we must not judge of the capacity of a man by the excellence of a happy remark that we heard him make. ...let us penetrate, says he, the mind from which it proceeds... it will oftenest be seen that he will be made to disavow it on the spot, and will be drawn very far from this better thought in which he does not believe, to plunge himself into another, quite base and ridiculous.
    • Montaigne, Essais, liv. III, chap. viii.—Faugère
  • I would inquire of reasonable persons whether this principle: Matter is naturally wholly incapable of thought, and this other: I think, therefore I am, are in fact the same in the mind of Descartes, and in that of St. Augustine, who said the same thing twelve hundred years before. ...I am far from affirming that Descartes is not the real author of it, even if he may have learned it only in reading this distinguished saint; for I know how much difference there is between writing a word by chance without making a longer and more extended reflection on it, and perceiving in this word an admirable series of conclusions, which prove the distinction between material and spiritual natures, and making of it a firm and sustained principle of a complete metaphysical system, as Descartes has pretended to do. is on this supposition that I say that this expression is as different in his writings from the saying in others who have said it by chance, as in a man full of life and strength, from a corpse.
    • see St. Augustine, Civitate Dei, 1. XI, c. xxvi
  • One man will say a thing of himself without comprehending its excellence, in which another will discern a marvelous series of conclusions, which makes us affirm that it is no longer the same expression, and that he is no more indebted for it to the one from whom he has learned it, than a beautiful tree belongs to the one who cast the seed, without thinking of it, or knowing it, into the fruitful soil which caused its growth by its own fertility.
  • Logic has borrowed, perhaps, the rules of geometry, without comprehending their force... it does not thence follow that they have entered into the spirit of geometry, and I should be greatly averse... to placing them on a level with that science that teaches the true method of directing reason.
  • The method of not erring is sought by all the world. The logicians profess to guide it, the geometricians alone attain it, and apart from science, and the imitations of it, there are no true demonstrations.
  • Nothing is more common than good things: the point in question is only to discriminate them; and it is certain that they are all natural and within our reach and even known to all mankind.
  • It is not among extraordinary and fantastic things that excellence is to be found, of whatever kind it may be. We rise to attain it and become removed from it: it is oftenest necessary to stoop for it.
  • The best books are those, which those who read them believe they themselves could have written.
  • Nature, which alone is good, is wholly familiar and common.
  • I make no doubt... that these rules are simple, artless, and natural.
  • The mind must not be forced; artificial and constrained manners fill it with foolish presumption, through unnatural elevation and vain and ridiculous inflation, instead of solid and vigorous nutriment.
  • One of the principal reasons that diverts those who are entering upon this knowledge so much from the true path which they should follow, is the fancy that they take at the outset that good things are inaccessible, giving them the name great, lofty, elevated, sublime. This destroys everything. I would call them low, common, familiar: these names suit it better; I hate such inflated expressions.

Quotes about Pascal

  • I was very fortunate. I was curious and handicapped as a young person. And so I read everything I could get my hands on and I have a good memory. And I have a lot of energy. It's a blessing. So I continued to learn. I'm hungry for knowledge still. Not every young person is blessed or visited with that combination. So he or she desperately needs to go to a university and be introduced to some of the great ideas of humankind. One needs to worry over the question of "Why am I here, what am I doing here of all things in this place, this life?" One needs to know Aristotle and Plato. One needs it desperately. One must have Leopold and Pascal. Must! I mean desperately, if one is to be at ease anywhere. One should have read the African folk tale to see what the West African calls deep thinking. One must worry over ideas that if I come forward how far do we have to go before we meet? And when we meet will I go through you and you go through me and continue until we meet someone else? This is an African concept. Do we stay once we meet or do I actually go right through you and pass through you and continue on that road. Is that what life is? All this knowledge is available at universities and one is more likely to run into a great teacher at a university than one is at a pool hall. It just follows.
  • It is significant that we owe the first explicit formulation of the principle of recurrence to the genius of Blaise Pascal... Pascal stated the principle in a tract called The Arithmetic Triangle which appeared in 1654. Yet... the gist of the tract was contained in the correspondence between Pascal and Fermat regarding a problem in gambling, the same correspondence which is now regarded as the nucleus from which developed the theory of probabilities.
    It surely is a fitting subject for mystic contemplation that the principle of reasoning by recurrence, which is so basic in pure mathematics, and the theory of probabilities, which is the basis of all deductive sciences, were both conceived while devising a scheme for the division of stakes in an unfinished match of two gamblers.
  • What Pascal said of an effective religion is true of any effective doctrine: It must be "contrary to nature, to common sense and to pleasure."

§56, referencing Pensées

Encyclical Populorom Progressio] (1967)

  • Pascal scornfully said that simple workmen had been able to convince of error those great men that are called 'philosophers'. It was, then, these unlearned men... who were most ready to believe 'what they saw with their eyes and touched with their hands'.
  • To philosophize is always to rehabilitate the essential importance of the human dimension, and hence the dignity of man. This was the meaning of the Socratic quest, and also the meaning of Pascal's anguish at the threshold of the Cartesian revolution in science. In this respect, Pascal is an even more significant figure of philosophy than Socrates: his was the first brutal reaction to the claim of science to remove man from his position as a privileged being in creation; nobody has so far been able to improve upon his demonstration why science is unsatisfactory to give man meaning and to fill his heart with joy.
    • Thomas Molnar, The Decline of the Intellectual (1961) Ch. 11 "Intellectual and Philosopher"
  • Pascal was no obscurantist, but he measured how far science (esprit de géometrie) may go and become irrelevant to the problems of human destiny. The achievements of science are not denied by this stand, nor are they dismissed as the ostrich with its head burrowed in sand dismisses reality. What is asserted is that our original endowments as they reflect on the data of experience, are, with all their limitations and imperfections, the only necessary and indispensable means by which we confront existence, the only weapon commensurate with our struggle.
    • Thomas Molnar, The Decline of the Intellectual (1961) Ch. 11 "Intellectual and Philosopher"
  • Pascal is a judicious critic of Descartes, not opposing him at all points, but opposing him nevertheless, on points that are fundamental. He perceived, first, that the Cartesian desire for certain knowledge was based upon a false criterion of certainty. Descartes must begin with something so sure that it cannot be doubted, and was led, as a consequence, to believe that all genuine knowledge is technical knowledge. Pascal avoided this conclusion by his doctrine of probability: the only knowledge that is certain is certain on account of its partiality; the paradox that probable knowledge has more of the whole truth than certain knowledge. Secondly, Pascal perceived that the Cartesian raisonnement is never in fact the whole source of the knowledge involved in any concrete activity. The human mind, he asserts, is not wholly dependent for its successful working upon a conscious and formulated technique; and even where a technique is involved, the mind observes the technique 'tacitement, naturellement et sans art' . The precise formulation of rules of inquiry endangers the success of the inquiry by exaggerating the importance of method. Pascal was followed by others, and indeed much of the history of modern philosophy revolves round this question. But, though later writers were often more elaborate in their criticism, few detected more surely than Pascal that the significance of Rationalism is not its recognition of technical knowledge, but its failure to recognize any other: its philosophical error lies in the certainty it attributes to technique and in its doctrine of the sovereignty of technique; its practical error lies in its belief that nothing but benefit can come from making conduct self-conscious.
    • Michael Oakeshott, "Rationalism in Politics" in Rationalism in Politics and other essays (1962)
  • Pascal is the only great mathematician whose standing is equally great among writers. Moreover, his devotion to the Jansenist ideal of serving the needy had one enduring practical consequence: his idea of a public transportation system. Shortly before his death... Pascal saw the inauguration of the world's first omnibus service. Coaches could be taken from the Porte Sainte-Antoine to the Luxembourg in Paris for 5 sous, with the profits being directed to the relief of the poor.
  • Against Pascal I say: The God of Abraham, Isaac, and Jacob and the God of the philosophers is the same God.
    • Paul Tillich, Biblical Religion and the Search for Ultimate Reality
  • Pascal's Thoughts are not a book. We must bear this observation in mind, if we are to judge of them aright. They are not a book; perhaps they may be two, or even more. They are — if we must give them a name and define them — they are Pascal himself — whole Pascal, excepting in so far as he was a geometrician, properly so called, and a natural philosopher. The Thoughts are only the papers on which this great man threw out, from time to time, all that occupied his powerful mind, until the excess of physical malady reduced him to complete inaction, and put, so to speak, the seals upon his genius. Great pains have been taken, and not without success, to reduce these scattered materials, by means of art, into a kind of whole. Sometimes, perhaps, the secret of the writer has been guessed; possibly, in certain cases, his intention has been entirely misunderstood.
  • Pascal proves nothing in favour of Religion, unless that a man of genius may be foolish on some subjects, and is but a child, when he is weak enough to listen to his prejudices.


  • There is a God-shaped vacuum in the heart of each man...
See quote about a "gouffre infini" on the Pensées page.


  • La netteté d’esprit cause aussi la netteté de la passion; c’est pourquoi un esprit grand et net aime avec ardeur, et il voit distinctement ce qu’il aime.
    • Clarity of mind means clarity of passion, too; this is why a great and clear mind loves ardently and sees distinctly what it loves.
    • Discours sur les passions de l'amour ('Discourse on the Passions of Love'), doubtfully attributed to Pascal.
  • Knowledge is like a sphere, the greater its volume, the larger its contact with the unknown.
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