The family goes back in 1649 to Paris, where Pascal finds in the entertainments society men a remedy for his trouble. His/her father dies in 1651, and his Jacqueline sister between the following year with the abbey of Port-Royal. By his friend the duke of Roannez, it is introduced into the company of the knight of Mother, of the libertine Of the Bars, and Mrs. de Sablé. One allots a Speech to him on passions of the love published in 1653, time to which Pascal founds the theory of probability and writes a Treaty of the arithmetic triangle.  

During the night of November 23rd, 1654, it has the revelation, in a kind of interior rapture, of the truth of the Christian religion: he discovers what will be the center of its thought: “God of Abraham, God of Isaac, God of Jacob, not of the philosophers and the scientists. Certainty. Feeling. Joy. Peace. God of Jesus-Christ (...) total and soft Renunciation. Tender with Jesus-Christ and my director.” It is with this spiritual adviser that it discusses Epictète and Montaigne at the time of a first retirement in Port-Royal. In two fragments on the geometrical spirit, he affirms that sciences prepare with better knowing God. In a polemic engaged against the Jesuits by Antoine Arnauld, Pascal takes the defense of the cause of Port-Royal: under the pseudonym of Louis de Montalte, it publishes, January 1656 to March 1657, Provincial the, made up ones of eighteen letters which have an immense repercussion. Pascal, who conceives the project of a work intended to prove the truth of the Christian religion, tries to solve, in the field of science, the problem of the “caster”, or cycloid, and provides the foundations of the infinitesimal calculus. Exhausted, demanding with mortifications, he writes Prière to ask to God the good use of the diseases.

Reason and religion

The Apology for the Christian religion, works to which Pascal devotes his last years, does not raise of rational theology, although she addresses herself to readers nourished of philosophy and got excited of ancient wisdom. It attaches to show that the human condition can be understood only in the light of the Writing, which reveals the history of the man, that of a deposed being. For him, the stoical philosophy of Epictète sins by pride by affirming that we are able to make our safety ourselves. In the same way, he criticizes the skepticism of Montaigne, which recognizes the impotence of the man but who puts up too much with it. Both wrongly allot the weaknesses and the man power to alleged “a human nature”. Pascal, who sees the failure of philosophy there, turns to the faith.  

What diverts Pascal of the philosophical ambition, in particular of the thought of Descartes, which it reproaches its confidence in a reason capable of truth, it is that supreme satisfaction, according to him, could not come from knowledge, even perfect, of nature. Moreover, the science of nature, or “natural philosophy”, leads by no means to the certainty, even less with wisdom. Applicant to legislate on control, the philosophers know neither the matter of which the body is made up nor the structure of the Universe, and their quarrels relate to the concept even of the sovereign well. The reason should give up seeking the bottom of the things to direct the existence.  

“To philosophize, it is to make fun of philosophy”
Each of the two opposite philosophic attitudes, namely the pyrrhonism - which recommend the radical doubt - and the dogmatism - which proclaims theses without subjecting them to the critical examination -, rests on partially right considerations: it is true that the philosophers have “impotence to prove”, but they have an idea of invincible truth the “to all the pyrrhonism”. From this contradiction of the partially true positions, which characterizes philosophy according to him, Pascal concludes that the reason cannot understand itself. In the geometry, its brighter success testifies, which bases its demonstrations on axioms, i.e. principles which themselves are not shown.  

The reason does not satisfy its own requirements because she does not manage to give an account of all the phenomena and all the human experiments. What one knows by the “heart” or by the “feeling” escapes from the geometry - the “most perfect order between the men” - and its method. The reason can seize the need, but, as one notes it in the geometry, this need is only formal. It is necessary however to avoid withdrawing any confidence to him or, on the contrary, trusting only it claiming about it that it can offer a strong foundation to our judgments. The only manner “really of philosophizing”, it is “to make fun of philosophy” and the reason.  

Just as the reason is neither impotent nor all-powerful, in the same way the man must be regarded as a medium between all and nothing. He is however not the center of the Universe, as affirms it humanism, nor a component of a harmonious unit, the cosmos, where the orders of the sky, Earth, gods and mortals would be treated on a hierarchical basis, as claimed it the Aristotelian philosophy, contradicted by modern science. Thus, the rational theology, which took again on its account the conceptual diagrams of the ancient thought, is null and void. From now on the skies answer our interrogations only by one alarming silence. Cosmology directs any more neither research of the truth nor the moral judgments.  
 
Misery and size of the man

Neither the reason nor sciences made up offer reliable benchmarks to distinguish the truth of the forgery: the man, “monster incomprehensible” which tries to know itself, is discovered as an abyss of contradictions, of “disproportion”. We never hold at time present, only to however be real, but we flee ourselves in the vain research of happiness; we hope for food, but we do not live. To drive out the thought of death, we deliver ourselves to the entertainment, which diverts us reflection on our condition, which is that of condemned to died in a dungeon. Multiform, the entertainment involves the men of all conditions, beggar and kings, with the war, the hunting or the part of charts. The philosophy, which is defined however as the research of the truth, misleads us; it creates the most pernicious illusion, because it does not work, in fact, through all its analyzes, that to relieve death of any reality.  

The man is the slave of the entertainment: with hunting, which it likes, it is to run after hare and not to take it, with the play and work to absorb itself while complaining, but he would groan if it were delivered his burdens. Size and misery are inseparable in the man; its size consists in thinking, and thus knowing its misery: “A tree does not know itself miserable. It is thus to be miserable which to know miserable; but is to be large to know which one is miserable.” The misery of the man is that of a “dispossessed king”.  

God is true knowledge
Threatened to be crushed by all the Universe, the man however has more dignity than what kills it. For little which he agrees to accommodate, the Christian religion reveals its fate to him: the man is a creature of God exiled in the world. Madness for the pagan ones, the strangeness of this religion consists in ordering to the man to recognize his lowness and, at the same time, to want to be similar to God, to thus claim in the highest place. The knowledge of God without that of human misery is source of pride; the knowledge of our misery without that of God is source of despair. Out of the knowledge of Jesus-Christ, in which we find at the same time God and human misery, there are only illusions. One of them consists in seeking “values” in the institutions and the human activities, whereas they meet only practical needs.

Pascal devaluates it to what humanistic wisdoms and morals attach highest dignity. Justice, pity, charity, the direction of the history are discredited at his place (later, they will seem at Nietzsche). For him, human justice is not justice, not more than charity or pity simply human are not charity or pity. “One was useful oneself as one could of the concupiscence to make it be used for the public property; but is to only pretend, and a false image of charity; because at the bottom it is only hatred.” Pascal denounces in pity a trick of the interest or a play of the superiority: “To feel sorry for the unhappy ones is not against the concupiscence. On the contrary, one is well ease to have to return this testimony of friendship, and to attract the reputation of tenderness, without nothing to give.”  

The order necessary
Just as in sciences we must be satisfied with the geometrical order and give up all showing, in the same way must us accept a conventional justice which can legitimate the most horrible practices. In fact, the right does not have anything universal (“joke justice which a river limits! ”), because it changes from one country to another: “Truth with-on this side of the Pyrenees, error beyond.” The established order has value only in what it maintains peace - avoiding the civil war, largest of the evils, and deciding between the claims of the men -, however, it is undoubtedly not reasonable. By adopting the rule to take for king the oldest son of the king, one avoids, like had affirmed it Montaigne, the disputes between applicants and captains who would not fail to aspire to the supreme power and to rise. There is thus no natural right: justice among the men is only this substantive law, founded on the force: “Being able to only make what is right strong barrel, it was made that what is strong barrel right.” Thus, it is not necessary to be astonished by little report which exists in the history between the most spectacular effects and their causes, negligible or ridiculous: a grain of sand in the ureter of Cromwell, the length of the nose of Cléopâtre are enough so that the war bursts or so that peace returns.  

Thinker of the radical distinction, which opposed the “natural sizes” - sciences, the virtue, health, the force - and the “sizes of establishment”, Pascal gives an account of the distress of the man in front of the absence of order.  
 
The heart and charity

The bodies, the spirits, charity (with the evangelic direction of love of god) do not have any common measurement between them, these “three orders” do not belong to any common order. The size of a scientist does not appear to a rich person nor with a captain. The size of Jesus-Christ is of another kind that of Archimedes. An infinite distance separates them, at the same time as “the infinite distance from the bodies to the spirits appears the distance infinitely more infinite from the spirits in charity”. Mathematics contributes to shake the man attached to the only certainty of the reason: that one adds a unit ad infinitum does not increase it; of an infinite number, it is also false to say that it is even or odd; a limited surface is made of an infinity of lines; a double segment of another does not contain more points than this one.

All these truths, rather understood that shown, like Pascal of the properties in the Treaty of the arithmetic triangle says it, prepare not to reject another comprehension by feeling. And so this “libertine” mathematics escapes, at least is not it foreign with the probabilities when he plays; it is by this skew that one can interest it in his safety. The reason not being able anything to determine concerning the existence of God, it is necessary “to bet”: there cannot remain indifferent when he goes there from an eternity of bliss. The more so as, even if it does not ensure its future life, while betting on God, the libertine does not lose anything in this life: he makes the choice of a less disappointing terrestrial life and escapes the “stunk out pleasures”. There is not infinity of loss, there is infinity of profit. Who wouldn't exchange nothing against the being?  

Pascal shares the thesis of Epictète according to which the man is tall by his thought, and it underlines with Montaigne the weakness and the brittleness of the reason. The inconsistency and the contradiction of the human nature can be indeed explained only if one refers to the supernatural destiny of the man, revealed by Christianity. The single goal is thus to cooperate with God “to incline the heart” of the man “mislaid in this corner of the Universe, without knowing what put it at it, which it came there to do, which it will become while dying”.