Great Throughts Treasury

"It must not be thought that it is ever possible to reach the interior earth by any perseverance in mining: both because the exterior earth is too thick, in comparison with human strength; and especially because of the intermediate waters, which would gush forth with greater impetus, the deeper the place in which their veins were first opened; and which would drown all miners."

"Let whoever can do so deceive me, he will never bring it about that I am nothing, so long as I continue to think I am something."

"Masked, I advance."

"One cannot conceive anything so strange and so implausible that it has not already been said by one philosopher or another."

"Perfect numbers like perfect men are very rare."

"It would be disingenuous, however, not to point out that some things are considered as morally certain, that is, as having sufficient certainty for application to ordinary life, even though they may be uncertain in relation to the absolute power of God."

"My first rule was to accept nothing as true which I did not clearly recognize to be so; to accept nothing more than what was presented to my mind so clearly and distinctly that I could have no occasion to doubt it. The second rule was to divide each problem or difficulty into as many parts as possible. The third rule was to commence my reflections with objects which were the simplest and easiest to understand, and rise thence, little by little, to knowledge of the most complex. The fourth rule was to make enumerations so complete, and reviews so general, that I should be certain to have omitted nothing."

"Of all things, good sense is the most fairly distributed: everyone thinks he is so well supplied with it that even those who are the hardest to satisfy in every other respect never desire more of it than they already have."

"Nothing comes out of nothing. [Ex nihilo nihil fit.]"

"Let us suppose, then, that we are dreaming, and that all these particulars--namely, the opening of the eyes, the motion of the head, the forth- putting of the hands--are merely illusions; and even that we really possess neither an entire body nor hands such as we see. Nevertheless it must be admitted at least that the objects which appear to us in sleep are, as it were, painted representations which could not have been formed unless in the likeness of realities; and, therefore, that those general objects, at all events, namely, eyes, a head, hands, and an entire body, are not simply imaginary, but really existent. For, in truth, painters themselves, even when they study to represent sirens and satyrs by forms the most fantastic and extraordinary, cannot bestow upon them natures absolutely new, but can only make a certain medley of the members of different animals; or if they chance to imagine something so novel that nothing at all similar has ever been seen before, and such as is, therefore, purely fictitious and absolutely false, it is at least certain that the colors of which this is composed are real. And on the same principle, although these general objects, viz. a body, eyes, a head, hands, and the like, be imaginary, we are nevertheless absolutely necessitated to admit the reality at least of some other objects still more simple and universal than these, of which, just as of certain real colors, all those images of things, whether true and real, or false and fantastic, that are found in our consciousness (cogitatio), are formed."

"Nothing is more evenly distributed in the world that the reason everyone is convinced of having enough."

"Nothing is more fairly distributed than common sense: no one thinks he needs more of it than he already has."

"Moral certainty is certainty which is sufficient to regulate our behaviour, or which measures up to the certainty we have on matters relating to the conduct of life which we never normally doubt, though we know that it is possible, absolutely speaking, that they may be false."

"The first was never to accept anything as true if I did not know clearly that it was so; that is, carefully to avoid prejudice and jumping to conclusions, and to include nothing in my judgments apart from whatever appeared so clearly and distinctly to my mind that I had no opportunity to cast doubt upon it."

"That the grace of fable stirs the mind... and... the perusal of excellent books is, as it were, to interview with the noblest men of past ages"

"The first precept was never to accept a thing as true until I knew it as such without a single doubt."

"The last rule was to make enumerations so complete, and reviews so comprehensive, that I should be certain of omitting nothing."

"The nature of matter, or body considered in general, consists not in its being something which is hard or heavy or colored, or which affects the senses in any way, but simply in its being something which is extended in length, breadth and depth."

"Some years ago I was struck by the large number of falsehoods that I had accepted as true in my childhood, and by the highly doubtful nature of the whole edifice that I had subsequently based on them. I realized that it was necessary, once in the course of my life, to demolish everything completely and start again right from the foundations if I wanted to establish anything at all in the sciences that was stable and likely to last."

"So blind is the curiosity by which mortals are possessed, that they often conduct their minds along unexplored routes, having no reason to hope for success, but merely being willing to risk the experiment of finding whether the truth they seek lies there."

"Staying as I am, one foot in one country and the other in another, I find my condition very happy, in that it is free."

"The greatest minds are capable of the greatest vices as well as of the greatest virtues. [The greatest minds, as they are capable of the highest excellencies, are open likewise to the greatest aberrations.]"

"The long chains of inferences, all of them simple and easy, that geometers normally use to construct their most difficult demonstrations had given me an opportunity to think that all the things that can fall within the scope of human knowledge follow from each other 'in a similar way, and as long as one avoids accepting something as true which is not so, and as long as one always observes the order required to deduce them from each other, there cannot be anything so remote that it cannot be reached nor anything so hidden that it cannot be uncovered."

"The principal effect of the passions is that they incite and persuade the mind to will the events for which they prepared the body."

"The object of music is a Sound. The end; to delight, and move various Affections in us."

"The seeker after truth must, once in the course of his life, doubt everything, as far as is possible."

"The senses deceive from time to time, and it is prudent never to trust wholly those who have deceived us even once."

"Then I had shown, in the same place, what the structure of the nerves and muscles of the human body would have to be in order for the animal spirits in the body to have the power to move its members, as one sees when heads, soon after they have been cut off, still move and bite the ground even though they are no longer alive; what changes must be made in the brain to cause waking, sleep and dreams; how light, sounds, odours, tastes, warmth and all the other qualities of external objects can impress different ideas on it through the senses; how hunger, thirst, and the other internal passions can also send their ideas there; what part of the brain should be taken as 'the common sense', where these ideas are received; what should be taken as the memory, which stores the ideas, and as the imagination, which can vary them in different ways and compose new ones and, by the same means, distribute the animal spirits to the muscles, cause the limbs of the body to move in as many different ways as our own bodies can move without the will directing them, depending on the objects that are present to the senses and the internal passions in the body. This will not seem strange to those who know how many different automata or moving machines can be devised by human ingenuity, by using only very few pieces in comparison with the larger number of bones, muscles, nerves, arteries, veins and all the other parts in the body of every animal. They will think of this body like a machine which, having been made by the hand of God, is incomparably better structured than any machine that could be invented by human beings, and contains many more admirable movements."

"The second was to subdivide each on the problems I was about to examine: into as many parts as would be possible and necessary to resolve them better."

"There is nothing more ancient than the truth."

"There is nothing so far removed from us to be beyond our reach, or so far hidden that we cannot discover it."

"The two operations of our understanding, intuition and deduction, on which alone we have said we must rely in the acquisition of knowledge"

"There is a difference between happiness, the supreme good, and the final end or goal toward which our actions ought to tend. For happiness is not the supreme good, but presupposes it, being the contentment or satisfaction of the mind which results from possessing it."

"There is nothing so strange and so unbelievable that it has not been said by one philosopher or another."

"There is nothing to master not be entirely our thoughts."

"There may indeed be those who would prefer to deny the existence of a God so powerful, rather than believe that all other things are uncertain. But let us not oppose them for the present, and grant that all that is here said of a God is a fable; nevertheless in whatever way they suppose that I have arrived at the state of being that I have reached -- whether they attribute it to fate or to accident, or make out that it is by a continual succession of antecedents, or by some other method -- since to err and deceive oneself is a defect, it is clear that the greater will be the probability of my being so imperfect as to deceive myself ever, as is the Author to whom they assign my origin the less powerful. To these reasons I have certainly nothing to reply, but at the end I feel constrained to confess that there is nothing in all that I formerly believed to be true, of which I cannot in some measure doubt, and that not merely through want of thought or through levity, but for reasons which are very powerful and maturely considered; so that henceforth I ought not the less carefully to refrain from giving credence to these opinions than to that which is manifestly false, if I desire to arrive at any certainty in the sciences."

"These long chains of perfectly simple and easy reasonings by means of which geometers are accustomed to carry out their most difficult demonstrations had led me to fancy that everything that can fall under human knowledge forms a similar sequence; and that so long as we avoid accepting as true what is not so, and always preserve the right order of deduction of one thing from another, there can be nothing too remote to be reached in the end, or to well hidden to be discovered."

"Thinking is another attribute of the soul; and here I discover what properly belongs to myself. This alone is inseparable from me. I am -- I exist: this is certain; but how often? As often as I think; for perhaps it would even happen, if I should wholly cease to think, that I should at the same time altogether cease to be. I now admit nothing that is not necessarily true: I am therefore, precisely speaking, only a thinking thing, that is, a mind, understanding, or reason, -- terms whose signification was before unknown to me. I am, however, a real thing, and really existent; but what thing? The answer was, a thinking thing. The question now arises, am I aught besides? I will stimulate my imagination with a view to discover whether I am not still something more than a thinking being. Now it is plain I am not the assemblage of members called the human body; I am not a thin and penetrating air diffused through all these members, or wind, or flame, or vapor, or breath, or any of all the things I can imagine; for I supposed that all these were not, and, without changing the supposition, I find that I still feel assured of my existence."

"Travelling is almost like talking with those of other centuries."

"This result could have been achieved either by his [God] endowing my intellect with a clear and distinct perception of everything about which I would ever deliberate, or simply by impressing the following rule so firmly upon my memory that I could never forget it: I should never judge anything that I do not clearly and distinctly understand."

"What then is the source of my errors? They are owing simply to the fact that, since the will extends further than the intellect, I do not contain the will within the same boundaries; rather, I also extend it to things I do not understand. Because the will is indifferent in regard to such matters, it easily turns away from the true and the good; and in this way I am deceived and I sin."

"To know what people really think, pay attention to what they do, rather than what they say."

"When someone says 'I am thinking, therefore I am, or I exist', he does not deduce existence from thought by means of a syllogism, but recognizes it as something self-evident by a simple intuition of the mind. This is clear from the fact that if he were deducing it by means of a syllogism, he would have to have had previous knowledge of the major premise 'Everything which thinks is, or exists'; yet in fact he learns it from experiencing in his own case that it is impossible that he should think without existing. It is in the nature of our mind to construct general propositions on the basis of our knowledge of particular ones."

"When it is not in our power to follow what is true, we ought to follow what is most probable."

"Whence then come my errors? They come from the sole fact that since the will is much wider in its range and compass than the understanding, I do not restrain it within the same bounds, but extend it also to things which I do not understand: and as the will is of itself indifferent to these, it easily falls into error and sin, and chooses the evil for the good, or the false for the true."

"When I consider this carefully, I find not a single property which with certainty separates the waking state from the dream. How can you be certain that your whole life is not a dream?"

"When writing about transcendental issues, be transcendentally clear."

"Whenever anyone has offended me, I try to raise my soul so high that the offense cannot reach it."

"With me everything turns into mathematics. [omnia apud me mathematica fiunt]"

"You just keep pushing. You just keep pushing. I made every mistake that could be made. But I just kept pushing."