Academics From France

"Il est dangereux d'avoir raison dans des choses où des hommes accrédités ont tort."

"Si Dieu nous a faits à son image, nous le lui avons bien rendu."

"Nous cherchons tous le bonheur, mais sans savoir où, comme les ivrognes qui cherchent leur maison, sachant confusément qu'ils en ont une."

"Prier Dieu c'est se flatter qu'avec des paroles on changera toute la nature."

"C'est une des superstitions de l'esprit humain d'avoir imaginé que la virginité pouvait être une vertu."

"Qui plume a, guerre a."

"The king [Frederic] has sent me some of his dirty linen to wash; I will wash yours another time."

"C'est le privilège du vrai génie, et surtout du génie qui ouvre une carrière, de faire impunément de grandes fautes."

"Il vaut mieux hasarder de sauver un coupable que de condamner un innocent."

"Les habiles tyrans ne sont jamais punis."

"Le premier qui fut roi fut un soldat heureux: Qui sert bien son pays n'a pas besoin d'aïeux."

"Mais qu'un marchand de chameaux excite une sédition dans sa bourgade; qu'associé à quelques malheureux coracites il leur persuade qu'il s'entretient avec l'ange Gabriel; qu'il se vante d'avoir été ravi au ciel, et d'y avoir reçu une partie de ce livre inintelligible qui fait frémir le sens commun à chaque page; que, pour faire respecter ce livre, il porte dans sa patrie le fer et la flamme; qu'il égorge les pères, qu'il ravisse les filles, qu'il donne aux vaincus le choix de sa religion ou de la mort, c'est assurément ce que nul homme ne peut excuser, à moins qu'il ne soit né Turc, et que la superstition n'étouffe en lui toute lumière naturelle."

"Ne peut-on pas remonter jusqu'à ces anciens scélérats, fondateurs illustres de la superstition et du fanatisme, qui, les premiers, ont pris le couteau sur l'autel pour faire des victimes de ceux qui refusaient d'etre leurs disciples?"

"Une seule partie de la physique occupe la vie de plusieurs hommes, et les laisse souvent mourir dans l'incertitude."

"Le secret d'ennuyer est celui de tout dire."

"Usez, n'abusez point; le sage ainsi l'ordonne. Je fuis également Épictète et Pétrone. L'abstinence ou l'excès ne fit jamais d'heureux."

"Aime la vérité, mais pardonne à l'erreur."

"Tout homme sensé, tout homme de bien, doit avoir la secte chrétienne en horreur."

"Le paradis terrestre est où je suis."

"Le superflu, chose très nécessaire."

"Tous les genres sont bons, hors le genre ennuyeux."

"Où est l'amitié est la patrie."

"Ainsi, presque tout est imitation. L'idée des Lettres persanes est prise de celle de l'Espion turc. Le Boiardo a imité le Pulci, l'Arioste a imité le Boiardo. Les esprits les plus originaux empruntent les uns des autres. Michel Cervantes fait un fou de son don Quichotte; mais Roland est-il autre chose qu'un fou? Il serait difficile de décider si la chevalerie errante est plus tournée en ridicule par les peintures grotesques de Cervantes que par la féconde imagination de l'Arioste. Métastase a pris la plupart de ses opéras dans nos tragédies françaises. Plusieurs auteurs anglais nous ont copiés, et n'en ont rien dit. Il en est des livres comme du feu de nos foyers; on va prendre ce feu chez son voisin, on l'allume chez soi, on le communique à d'autres, et il appartient à tous."

"If there were only one religion in England there would be danger of despotism, if there were two they would cut each other's throats, but there are thirty, and they live in peace and happiness."

"Go into the London Stock Exchange – a more respectable place than many a court – and you will see representatives from all nations gathered together for the utility of men. Here Jew, Mohammedan and Christian deal with each other as though they were all of the same faith, and only apply the word infidel to people who go bankrupt. Here the Presbyterian trusts the Anabaptist and the Anglican accepts a promise from the Quaker."

"Les anciens Romains élevaient des prodiges d'architecture pour faire combattre des bêtes."

"Les mortels sont égaux; ce n'est pas la naissance, C'est la seule vertu qui fait la différence."

"L'homme est libre au moment qu'il veut l'être."

"C'est un poids bien pesant qu'un nom trop tôt fameux."

"On doit des égards aux vivants; on ne doit aux morts que la vérité."

"La vertu s'avilit à se justifier."

"If I had had more time, this letter would have been shorter."

"L'amour est de toutes les passions la plus forte, parce qu'elle attaque à la fois la tête, le cœur et le corps."

"Le public est une bête féroce: il faut l'enchaîner ou la fuir."

"L'homme doit être content, dit-on; mais de quoi?"

"On parle toujours mal quand on n'a rien à dire."

"It is often said that experiments should be made without preconceived ideas. That is impossible. Not only would it make every experiment fruitless, but even if we wished to do so, it could not be done. Every man has his own conception of the world, and this he cannot so easily lay aside. We must, for example, use language, and our language is necessarily steeped in preconceived ideas."

"If we study the history of science we see happen two inverse phenomena... Sometimes simplicity hides under complex appearances; sometimes it is the simplicity which is apparent, and which disguises extremely complicated realities. ...No doubt, if our means of investigation should become more and more penetrating, we should discover the simple under the complex, then the complex under the simple, then again the simple under the complex, and so on, without our being able to foresee what will be the last term. We must stop somewhere, and that science may be possible, we must stop when we have found simplicity. This is the only ground on which we can rear the edifice of our generalizations."

"Le savant doit ordonner ; on fait la science avec des faits comme une maison avec des pierres ; mais une accumulation de faits n'est pas plus une science qu'un tas de pierres n'est une maison."

"... les traités de mécanique ne distinguent pas bien nettement ce qui est expérience, ce qui est raisonnement mathématique, ce qui est convention, ce qui est hypothèse."

"What is mass? According to Newton, it is the product of the volume by the density. According to Thomson and Tait, it would be better to say that density is the quotient of the mass by the volume. What is force? It, is replies Lagrange, that which moves or tends to move a body. It is, Kirchhoff will say, the product of the mass by the acceleration. But then, why not say the mass is the quotient of the force by the acceleration? These difficulties are inextricable. When we say force is the cause of motion, we talk metaphysics, and this definition, if one were content with it, would be absolutely sterile. For a definition to be of any use, it must teach us to measure force; moreover that suffices; it is not at all necessary that it teach us what force is in itself, nor whether it is the cause or the effect of motion. We must therefore first define the equality of two forces. When shall we say two forces are equal? It is, we are told, when, applied to the same mass, they impress upon it the same acceleration, or when, opposed directly one to the other, they produce equilibrium. This definition is only a sham. A force applied to a body can not be uncoupled to hook it up to another body, as one uncouples a locomotive to attach it to another train. It is therefore impossible to know what acceleration such a force, applied to such a body, would impress upon such an other body, if it were applied to it. It is impossible to know how two forces which are not directly opposed would act, if they were directly opposed. We are... obliged in the definition of the equality of the two forces to bring in the principle of the equality of action and reaction; on this account, this principle must no longer be regarded as an experimental law, but as a definition."

"Is the position tenable, that certain phenomena, possible in Euclidean space, would be impossible in non-Euclidean space, so that experience, in establishing these phenomena, would directly contradict the non-Euclidean hypothesis? For my part I think no such question can be put. To my mind it is precisely equivalent to the following, whose absurdity is patent to all eyes: are there lengths expressible in meters and centimeters, but which can not be measured in fathoms, feet, and inches, so that experience, in ascertaining the existence of these lengths, would directly contradict the hypothesis that there are fathoms divided into six feet?"

"We see that experience plays an indispensable role in the genesis of geometry; but it would be an error thence to conclude that geometry is, even in part, an experimental science. If it were experimental it would be only approximative and provisional. And what rough approximation! ...The object of geometry is the study of a particular 'group'; but the general group concept pre-exists... in our minds. It is imposed on us, not as form of our sense, but as form of our understanding. Only, from among all the possible groups, that must be chosen... will be... the standard to which we shall refer natural phenomena. Experience guides us in this choice without forcing it upon us; it tells us not which is the truest geometry, but which is the most convenient. Notice that I have been able to describe the fantastic worlds... imagined without ceasing to employ the language of ordinary geometry."

"Les mathématiciens n'étudient pas des objets, mais des relations entre les objets ; il leur est donc indifférent de remplacer ces objets par d'autres, pourvu que les relations ne changent pas. La matière ne leur importe pas, la forme seule les intéresse."

"But, one will say, if raw experience can not legitimatize reasoning by recurrence, is it so of experiment aided by induction? We see successively that a theorem is true of the number 1, of the number 2, of the number 3 and so on; the law is evident, we say, and it has the same warranty as every physical law based on observations, whose number is very great but limited. But there is an essential difference. Induction applied to the physical sciences is always uncertain, because it rests on the belief in a general order of the universe, an order outside of us. Mathematical induction, that is, demonstration by recurrence, on the contrary, imposes itself necessarily, because it is only the affirmation of a property of the mind itself."

"We can not... escape the conclusion that the rule of reasoning by recurrence is irreducible to the principle of contradiction. ...Neither can this rule come to us from experience... This rule, inaccessible to analytic demonstration and to experience, is the veritable type of the synthetic a priori judgment. On the other hand, we can not think of seeing in it a convention, as in some of the postulates of geometry. ...it is only the affirmation of the power of the mind which knows itself capable of conceiving the indefinite repetition of the same act when once this act is possible. The mind has a direct intuition of this power, and experience can only give occasion for using it and thereby becoming conscious of it."

"This procedure is the demonstration by recurrence. We first establish a theorem for n = 1; then we show that if it is true of n - 1, it is true of n, and thence conclude that it is true for all the whole numbers. ..Here then we have the mathematical reasoning par excellence, and we must examine it more closely. ...The essential characteristic of reasoning by recurrence is that it contains, condensed, so to speak, in a single formula, an infinity of syllogisms. ...to arrive at the smallest theorem [we] can not dispense with the aid of reasoning by recurrence, for this is an instrument which enables us to pass from the finite to the infinite. This instrument is always useful, for, allowing us to overleap at a bound as many stages as we wish, it spares us verifications, long, irksome and monotonous, which would quickly become impracticable. But it becomes indispensable as soon as we aim at the general theorem... In this domain of arithmetic,.. the mathematical infinite already plays a preponderant rôle, and without it there would be no science, because there would be nothing general."

"There is no science apart from the general. It may even be said that the very object of the exact sciences is to spare us these direct verifications."

"The very possibility of the science of mathematics seems an insoluble contradiction. If this science is deductive only in appearance, whence does it derive that perfect rigor no one dreams of doubting? If, on the contrary, all the propositions it enunciates can be deduced one from another by the rules of formal logic, why is not mathematics reduced to an immense tautology? The syllogism can teach us nothing essentially new, and, if everything is to spring from the principle of identity, everything should be capable of being reduced to it. Shall we then admit that the enunciations of all those theorems which fill so many volumes are nothing but devious ways of saying A is A! ...Does the mathematical method proceed from particular to the general, and, if so, how can it be called deductive? ...If we refuse to admit these consequences, it must be conceded that mathematical reasoning has of itself a sort of creative virtue and consequently differs from a syllogism."

"Douter de tout ou tout croire, ce sont deux solutions également commodes, qui l'une et l'autre nous dispensent de réfléchir."