Finally ive ought to employ all the aids of understanding, imagi- nation, sense and memory, first for the purpose of having a distinct intuition of simple propositions ; partly also in order to compare the propositions to be proved with those ive know already, so that we may be able to recognize their truth ; partly also in order to discover the truths, which should be compared with each other so…

The end of study should be to direct the mind towards the enunciation of sound and correct judgments on all matters that come befoi~e it. Whenever men notice some similarity between two things, they are wont to ascribe to each, even in those respects in which the two differ, what they have found to be true of the other. Thus they erroneously compare the sciences, which entirely consist in the… Read the rest of this passage →

We ought to give the whole of our attention to the most insignifi- cant and most easily mastered facts, and remain a long time in contemplation of them until we are accustomed to behold the truth clearly and distinctly. We have now indicated the two operations of our understanding, ] intuition and deduction, on which alone we have said we must rely in the acquisition of knowledge. Let us… Read the rest of this passage →

The same rule is to be applied also to the real extension of bodies. It must be set before the imagination by means of mere figures, for this is the best way to make it clear to the understanding. But2 in proposing to make use of the imagination as an aid to our thinking, we must note that whenever one unknown fact is deduced from another that is already known, that does not show that we… Read the rest of this passage →

Once a 'question ' is perfectly understood, we must free it of every conception superfluous to its meaning, state it in its simplest terms, and, having recourse to an enumeration, split it up into the carious sections beyond which analysis cannot go in minuteness. This is the only respect in which we imitate the Dialecticians ; just as they, in teaching their doctrine of the forms of syllogism,…

In order that it may acquire sagacity the mind should be exercised in pursuing just those inquiries of which the solution has already been found by others ; and it ought to traverse in a systematic way even the most trifling of men's inventions, though those ought to be preferred in which order is explained or implied. I confess that my natural disposition is such that I have always found, not…

Only those objects should engage our attention, to the sure and indubitable knowledge of ivhich our mental powers1 seem to be adequate. Science in its entirety is true and evident cognition. He is no more learned who has doubts on many matters than the man who has never thought of them ; nay he appears to be less learned if he has formed wrong opinions on any particulars. Hence it were better…

In the subjects we propose to investigate, our inquiries should be directed, not to what others have thought2, nor to what we ourselves conjecture, but to what we can clearly and perspicuously behold and with certainty deduce ; for knowledge is not won in any other way. To study the writings of the ancients is right, because it is a great boon for us to be able to make use of the labours of so…

There is need of a method for finding out the truth. 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. As well might a man burning with an unintelligent desire to find treasure, continuously… Read the rest of this passage →

If in tlie matters to be examined we come to a step in the series of which our understanding is not sufficiently well able to have am intuitive cognition, we must stop short there. We must make no attempt to examine what follows; thus ice shall spare ourselves superfluous labour. 1 Cf. . For Direction 23 The three preceding rules prescribe and explain the order to be followed. The present…

In order to separate out what is quite simple from ivhat is complex, and to arrange these matters methodically, we ought, in the case of every series in which ive have deduced certain facts the one from the other, to notice which fact is simple, and to mark the interval, greater, less, or equal, which separates all the others from this. Although this proposition seems to teach nothing very new,… Read the rest of this passage →

When we come across matters which do not require our present attention, it is better, even though they are necessary to our conclusion, to represent them by highly abbreviated symbols, rather than by complete figures. This guards against error due to defect of memory on the one hand, and, on the other, prevents that distractio?i of thought which an effort to keep those matters in mind while… Read the rest of this passage →

If we wish our science to be complete, those matters which promote the end we have in view must one and all be scrutinized by a move- ment of thought which is continuous and nowhere interrupted ; they must also be included in an enumeration which is both adequate and methodical. It is necessary to obey the injunctions of this rule if we hope to gain admission among the certain truths for those… Read the rest of this passage →

Method consists entirely in the order and disposition of the objects towards which our mental vision must be directed if we would find out any truth. We shall comply with it exactly if we reduce involved and obscure propositions step by step to those that are simpler, and then starting with the intuitive apprehension of all those that are absolutely simple, attempt to ascend to the knowledge of…

MEDITATION I Of the things which may be brought within the sphere of the doubtful. It is now some years since I detected how many were the false beliefs that I had from my earliest youth admitted as true, and how doubtful was everything I had since constructed on this basis; and from that time I was convinced that I must once for all seriously undertake to rid myself of all the opinions which I… Read the rest of this passage →

OBJECTIONS URGED BY CERTAIN MEN OF LEARNING AGAINST THE PRECEDING MEDITATIONS; WITH THE AUTHOR’S REPLIES THE FIRST SET OF OBJECTIONS^ Gentlemen, As soon as I recognized that you loere so anxious that I should make a thorough examination of the writings of M. Descartes^ it seemed impossible for me, in duty, to disoblige in this 7natier friends so dear to me. My reason in complying was both that… Read the rest of this passage →

OOD SENSE is of all things in the world the lost equally distributed, for everybody thinks imself so abundantly provided with it, that /en those most difficult to please in all other latters do not commonly desire more of it lan they already possess. It is unlikely that lis is an error on their part; it seems rather to s evidence in support of the view that the ower of forming a good judgment and… Read the rest of this passage →

Icnowledge of the lengths of certain straight lines is sufiS.cient for its construction. Just as arithmetic consists of only four or five operations, namely, addition, subtraction, multiplication, division and the extraction of roots, which may be considered a kind of division, so in geometry, to find required lines it is merely necessary to add or subtract other lines; or else, taking one line… Read the rest of this passage →