Music is a hidden arithmetic exercise of the soul, which does not know that it is counting.

I am convinced that the unwritten knowledge scattered among men of different callings surpasses in quantity and in importance anything we find in books, and that the greater part of our wealth has yet to be recorded.

There are two kinds of truths: those of reasoning and those of fact. The truths of reasoning are necessary and their opposite is impossible; the truths of fact are contingent and their opposites are possible.

Only geometry can hand us the thread [which will lead us through] the labyrinth of the continuum's composition, the maximum and the minimum, the infinitesimal and the infinite; and no one will arrive at a truly solid metaphysic except he who has passed through this [labyrinth].

I have said more than once, that I hold space to be something purely relative, as time; an order of coexistences, as time is an order of successions.

Even in the games of children there are things to interest the greatest mathematician.

Look round the world: contemplate the whole and every part of it: You will find it to be nothing but one great machine, subdivided into an infinite number of lesser machines, which again admit of subdivisions, to a degree beyond what human senses and faculties can trace and explain. All these various machines, and even their most minute parts, are adjusted to each other with an accuracy, which ravishes into admiration all men, who have ever contemplated them. The curious adapting of means to ends, throughout all nature, resembles exactly, though it much exceeds, the productions of human contrivance; of human design, thought, wisdom, and intelligence.

The slaving Poor are incapable of any Principles: Gentlemen may be converted to true Principles, by Time and Experience. The middling Rank of Men have Curiosity and Knowledge enough to form Principles, but not enough to form true ones, or correct any Prejudices that they may have imbib'd: And 'tis among the middling Rank, that Tory Principles do at present prevail most in England.

The sentiments of men often differ with regard to beauty and deformity of all kinds, even while their general discourse is the same ... In all matters of opinion and science, the case is opposite: The difference among men is there oftener found to lie in generals than in particulars; and to be less in reality than in appearance.

Were a stranger to drop on a sudden into this world, I would show him, as a specimen of its ills, a hospital full of diseases, a prison crowded with malefactors and debtors, a field of battle strewed with carcasses, a fleet foundering in the ocean, a nation languishing under tyranny, famine, or pestilence. To turn the gay side of life to him, and give him a notion of its pleasures; whither should I conduct him? to a ball, to an opera, to court? He might justly think, that I was only showing him a diversity of distress and sorrow.

People who invented the word charity, and used it in a good sense, inculcated more clearly, and much more efficaciously, the precept, Be charitable, than any pretended legislator or prophet, who should insert such a maxim in his writings.

What peculiar privilege has this little agitation of the brain which we call thought, that we must thus make it the model of the whole universe? Our partiality in our own favour does indeed present it on all occasions; but sound philosophy ought carefully to guard against so natural an illusion.

Avarice, the spur of industry, is so obstinate a passion, and works its way through so many real dangers and difficulties, that it is not likely to be scared by an imaginary danger, which is so small, that it scarcely admits of calculation. Commerce, therefore, in my opinion, is apt to decay in absolute governments, not because it is there less secure, but because it is less honourable.

It is natural for us to seek a Standard of Taste; a rule, by which the various sentiments of men may be reconciled; at least, a decision, afforded, confirming one sentiment, and condemning another.

Look round this universe. What an immense profusion of beings, animated and organised, sensible and active! You admire this prodigious variety and fecundity. But inspect a little more narrowly these living existences, the only beings worth regarding. How hostile and destructive to each other! How insufficient all of them for their own happiness! How contemptible or odious to the spectator! The whole presents nothing but the idea of a blind Nature, impregnated by a great vivifying principle, and pouring forth from her lap, without discernment or parental care, her maimed and abortive children!

All sentiment is right; because sentiment has a reference to nothing beyond itself, and is always real, wherever a man is conscious of it. But all determinations of the understanding are not right; because they have a reference to something beyond themselves, to wit, real matter of fact; and are not always conformable to that standard.

If reason (I mean abstract reason, derived from inquiries a priori) be not alike mute with regard to all questions concerning cause and effect, this sentence at least it will venture to pronounce, That a mental world, or universe of ideas, requires a cause as much, as does a material world, or universe of objects; and, if similar in its arrangement, must require a similar cause. For what is there in this subject, which should occasion a different conclusion or inference? In an abstract view, they are entirely alike; and no difficulty attends the one supposition, which is not common to both of them.

It is a great mortification to the vanity of man, that his utmost art and industry can never equal the meanest of nature's productions, either for beauty or value. Art is only the under-workman, and is employed to give a few strokes of embellishment to those pieces, which come from the hand of the master.

But though all the general rules of art are founded only on experience and on the observation of the common sentiments of human nature, we must not imagine, that, on every occasion, the feelings of men will be conformable to these rules.

If the whole of natural theology, as some people seem to maintain, resolves itself into one simple, though somewhat ambiguous, at least undefined proposition, that the cause or causes of order in the universe probably bear some remote analogy to human intelligence: If this proposition be not capable of extension, variation, or more particular explication: If it affords no inference that affects human life, or can be the source of any action or forbearance: And if the analogy, imperfect as it is, can be carried no farther than to the human intelligence, and cannot be transferred, with any appearance of probability, to the other qualities of the mind; if this really be the case, what can the most inquisitive, contemplative, and religious man do more than give a plain, philosophical assent to the proposition, as often as it occurs, and believe that the arguments on which it is established exceed the objections which lie against it?

Beauty is no quality in things themselves: It exists merely in the mind which contemplates them; and each mind perceives a different beauty. One person may even perceive deformity, where another is sensible of beauty; and every individual ought to acquiesce in his own sentiment, without pretending to regulate those of others.

If the material world rests upon a similar ideal world, this ideal world must rest upon some other; and so on, without end. It were better, therefore, never to look beyond the present material world. By supposing it to contain the principle of its order within itself, we really assert it to be God; and the sooner we arrive at that Divine Being, so much the better. When you go one step beyond the mundane system, you only excite an inquisitive humour which it is impossible ever to satisfy.

Art may make a suit of clothes; but nature must produce a man.

But though there be naturally a wide difference in point of delicacy between one person and another, nothing tends further to encrease and improve this talent, than practice in a particular art, and the frequent survey or contemplation of a particular species of beauty.

Truth springs from argument amongst friends.

Every thing in the world is purchased by labour.

You need only look around you, replied PHILO, to satisfy yourself with regard to this question. A tree bestows order and organisation on that tree which springs from it, without knowing the order; an animal in the same manner on its offspring; a bird on its nest; and instances of this kind are even more frequent in the world than those of order, which arise from reason and contrivance. To say, that all this order in animals and vegetables proceeds ultimately from design, is begging the question; nor can that great point be ascertained otherwise than by proving, a priori, both that order is, from its nature, inseparably attached to thought; and that it can never of itself, or from original unknown principles, belong to matter.

If nature has been frugal in her gifts and endowments, there is the more need of art to supply her defects. If she has been generous and liberal, know that she still expects industry and application on our part, and revenges herself in proportion to our negligent ingratitude. The richest genius, like the most fertile soil, when uncultivated, shoots up into the rankest weeds; and instead of vines and olives for the pleasure and use of man, produces, to its slothful owner, the most abundant crop of poisons.

The same good sense, that directs men in the ordinary occurrences of life, is not hearkened to in religious matters, which are supposed to be placed altogether above the cognizance of human reason.

The heights of popularity and patriotism are still the beaten road to power and tyranny ; flattery to treachery ; standing armies to arbitrary government ; and the glory of God to the temporal interest of the clergy.

In a word, human life is more governed by fortune than by reason; is to be regarded more as a dull pastime than as a serious occupation; and is more influenced by particular humour, than by general principles. Shall we engage ourselves in it with passion and anxiety? It is not worthy of so much concern. Shall we be indifferent about what happens? We lose all the pleasure of the game by our phlegm and carelessness. While we are reasoning concerning life, life is gone; and death, though perhaps they receive him differently, yet treats alike the fool and the philosopher.

In such a chain, too, or succession of objects, each part is caused by that which preceded it, and causes that which succeeds it. Where then is the difficulty? But the WHOLE, you say, wants a cause. I answer, that the uniting of these parts into a whole, like the uniting of several distinct countries into one kingdom, or several distinct members into one body, is performed merely by an arbitrary act of the mind, and has no influence on the nature of things. Did I show you the particular causes of each individual in a collection of twenty particles of matter, I should think it very unreasonable, should you afterwards ask me, what was the cause of the whole twenty. This is sufficiently explained in explaining the cause of the parts.

The great end of all human industry, is the attainment of happiness. For this were arts invented, sciences cultivated, laws ordained, and societies modelled, by the most profound wisdom of patriots and legislators.

Any question of philosophy ... which is so obscure and uncertain, that human reason can reach no fixed determination with regard to it; if it should be treated at all; seems to lead us naturally into the style of dialogue and conversation.

In all ages of the world, priests have been enemies to liberty; and it is certain, that this steady conduct of theirs must have been founded on fixed reasons of interest and ambition. Liberty of thinking, and of expressing our thoughts, is always fatal to priestly power, and to those pious frauds, on which it is commonly founded; and, by an infallible connexion, which prevails among all kinds of liberty, this privilege can never be enjoyed, at least has never yet been enjoyed, but in a free government.

His character does not appear more extraordinary and unusual by the mixture of so much absurdity with so much penetration, than by his tempering such violent ambition, and such enraged fanaticism with so much regard to justice and humanity.

And why should man, added he, pretend to an exemption from the lot of all other animals? The whole earth, believe me, PHILO, is cursed and polluted. A perpetual war is kindled amongst all living creatures. Necessity, hunger, want, stimulate the strong and courageous: Fear, anxiety, terror, agitate the weak and infirm. The first entrance into life gives anguish to the new-born infant and to its wretched parent: Weakness, impotence, distress, attend each stage of that life: and it is at last finished in agony and horror.

A propensity to hope and joy is real riches: One to fear and sorrow, real poverty.

We speak not strictly and philosophically when we talk of the combat of passion and of reason. Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them.

How can you worship leeks and onions? we shall suppose a SORBONNIST to say to a priest of SAIS. If we worship them, replies the latter; at least, we do not, at the same time, eat them. But what strange object of adoration are cats and monkeys? says the learned doctor. They are at least as good as the relics or rotten bones of martyrs, answers his no less learned antagonist. Are you not mad, insists the Catholic, to cut one another's throat about the preference of a cabbage or a cucumber? Yes, says the pagan; I allow it, if you will confess, that those are still madder, who fight about the preference among volumes of sophistry, ten thousand of which are not equal in value to one cabbage or cucumber.

We must therefore glean up our experiments in this science from a cautious observation of human life, and take them as they appear in the common course of the world, by men's behaviour in company, in affairs, and in their pleasures. Where experiments of this kind are judiciously collected and compared, we may hope to establish on them a science, which will not be inferior in certainty, and will be much superior in utility to any other of human comprehension.

I say, then, that belief is nothing but a more vivid, lively, forcible, firm, steady conception of an object, than what the imagination alone is ever able to attain.

Grief and disappointment give rise to anger, anger to envy, envy to malice, and malice to grief again, till the whole circle be completed.

In all determinations of morality, this circumstance of public utility is ever principally in view; and wherever disputes arise, either in philosophy or common life, concerning the bounds of duty, the question cannot, by any means, be decided with greater certainty, than by ascertaining, on any side, the true interests of mankind. If any false opinion, embraced from appearances, has been found to prevail; as soon as farther experience and sounder reasoning have given us juster notions of human affairs, we retract our first sentiment, and adjust anew the boundaries of moral good and evil.

The life of man is of no greater importance to the universe than that of an oyster.

This avidity alone, of acquiring goods and possessions for ourselves and our nearest friends, is insatiable, perpetual, universal, and directly destructive of society.

The whole is a riddle, an aenigma, an inexplicable mystery. Doubt, uncertainty, suspence of judgment appear the only result of our most accurate scrutiny, concerning this subject. But such is the frailty of human reason, and such the irresistible contagion of opinion, that even this deliberate doubt could scarcely be upheld; did we not enlarge our view, and opposing one species of superstition to another, set them a quarrelling; while we ourselves, during their fury and contention, happily make our escape, into the calm, though obscure, regions of philosophy.

By this means all knowledge degenerates into probability; and this probability is greater or less, according to our experience of the veracity or deceitfulness of our understanding, and according to the simplicity or intricacy of the question.

In our reasonings concerning matter of fact, there are all imaginable degrees of assurance, from the highest certainty to the lowest species of moral evidence. A wise man, therefore, proportions his belief to the evidence.

There is an inconvenience which attends all abstruse reasoning. That it may silence, without convincing an antagonist, and requires the same intense study to make us sensible of its force, that was at first requisite for its invention. When we leave our closet, and engage in the common affairs of life, its conclusions seem to vanish, like the phantoms of the night on the appearance of the morning; and 'tis difficult for us to retain even that conviction, which we had attain'd with difficulty.