150 René Descartes Quotes on Truth, Doubt, and Logic

If you’re looking for René Descartes quotes to help you find the solution to your problems, then this is for you!

René Descartes was a great mathematician, philosopher, and writer. He introduced skepticism as a significant element of the scientific method. This is an approach that uses doubt as the starting point in solving a problem.

His philosophies continue to inspire us to learn about life. His words serve as reminders to not be gullible and to be curious at all times. Check out these wise quotes to learn more about his ideas.

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Best René Descartes Quotes

1. “Conquer yourself rather than the world.”

2. “I doubt, therefore I think, therefore I am.”

3. “The greatest minds are capable of the greatest vices as well as of the greatest virtues.”

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

5. “To live without philosophizing is in truth the same as keeping the eyes closed without attempting to open them.”

6. “An optimist may see a light where there is none, but why must the pessimist always run to blow it out?”

7. “The reading of all good books is like conversation with the finest men of past centuries.”

8. “We do not describe the world we see, we see the world we can describe.”

9. “A state is better governed which has few laws, and those laws strictly observed.”

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

11. “It is not enough to have a good mind; the main thing is to use it well.”

12. “Truths will be discovered by an individual rather than a whole people.”

13. “I am accustomed to sleep, and in my dreams to imagine the same things that lunatics imagine when awake.”

14. “If you would be a real seeker after truth, it is necessary that at least once in your life you doubt, as far as possible, all things.”

15. “It is only prudent never to place complete confidence in that by which we have even once been deceived.”

Famous René Descartes Quotes

16. “Doubt is the origin of wisdom.”

17. “The only thing that I know, is that I know nothing.”

18. “Because reason is the only thing that makes us men and distinguishes us from the beasts, I would prefer to believe that it exists, in its entirety, in each of us.”

19. “I am indeed amazed when I consider how weak my mind is and how prone to error.”

20. “Each problem that I solved became a rule, which served afterward to solve other problems.”

21. “I know that I exist; the question is, what is this ‘I’ that ‘I’ know?”

22. “Perfect numbers like perfect men are very rare.”

23. “Control your body if you want your mind to work properly.”

24. “Except our own thoughts, there is nothing absolutely in our power.”

25. “Our convictions result from custom and example very much more than from any knowledge that is certain.”

26. “Divide each difficulty into as many parts as is feasible and necessary to resolve it.”

27. “I hope that posterity will judge me kindly, not only as to the things which I have explained but also to those which I have intentionally omitted so as to leave to others the pleasure of discovery.”

28. “The chief cause of human errors is to be found in the prejudices picked up in childhood.”

29. “Common sense is the most fairly distributed thing in the world, for each one thinks he is so well-endowed with it that even those who are hardest to satisfy in all other matters are not in the habit of desiring more of it than they already have.”

30. “The thinking of the mind is twofold; understanding and willing.”

Wise René Descartes Quotes to Live By

31. “Illusory joy is often worth more than genuine sorrow.”

32. “Wonder is the first of all the passions.”

33. “If you want to develop your mind you should think more, not repeat.”

34. “To know what people really think, pay regard to what they do, rather than what they say.”

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

36. “The two operations of our understanding, intuition, and deduction, on which alone we have said we must rely on the acquisition of knowledge.”

37. “Like a prisoner who dreams that he is free, starts to suspect that it is merely a dream, and wants to go on dreaming rather than waking up, so I am content to slide back into my old opinions; I fear being shaken out of them because I am afraid that my peaceful sleep may be followed by hard labor when I wake and that I shall have to struggle not in the light but in the imprisoning darkness of the problems I have raised.”

38. “You just keep pushing. You just keep pushing. I made every mistake that could be made. But I just kept pushing.”

39. “Any community that gets its laughs by pretending to be idiots will eventually be flooded by actual idiots who mistakenly believe that they’re in good company.”

40. “I desire to live in peace and to continue the life I have begun under the motto ‘to live well you must live unseen.”

41. “It is in the nature of our mind to construct general propositions on the basis of our knowledge of particular ones.”

42. “At last I will devote myself sincerely and without reservation to the general demolition of my opinions.”

43. “Your joy is your sorrow unmasked. And the selfsame well from which your laughter rises was oftentimes filled with your tears.”

44. “In order to improve the mind, we ought less to learn, than to contemplate.”

45. “My third maxim was to try always to conquer myself rather than fortune, and to change my desires rather than the order of the world, and generally to accustom myself to believing that there is nothing entirely in our power except our thoughts so that after we have done our best regarding things external to us, everything in which we do not succeed is for us absolutely impossible.”

Short but Profound René Descartes Quotes 

46. “He who hid well, lived well.”

47. “Nothing comes out of nothing.”

48. “Everything is self-evident.”

49. “All is to be doubted.”

50. “Masked, I advance.”

René Descartes Quotes on Truth and Doubt

51. “If—it is not in my power to arrive at the knowledge of any truth—I may at least do what is in my power, namely, suspend judgment.”

52. “For I found myself embarrassed with so many doubts and errors that it seemed to me that the effort to instruct myself had no effect, other than the increasing discovery of my own ignorance.”

53. “If I simply refrain from making a judgment in cases where I do not perceive the truth with sufficient clarity and distinctness, then it is clear that I am behaving correctly and avoiding error.”

54. “I can doubt everything, except one thing, and that is the very fact that I doubt.”

55. “Desire awakens only to things that are thought possible.”

56. “In philosophy, when we make use of false principles, we depart the farther from the knowledge of truth and wisdom exactly in proportion to the care with which we cultivate them, and apply ourselves to the deduction of diverse consequences from them, thinking that we are philosophizing well, while we are only departing the farther from the truth; from which it must be inferred that they who have learned the least of all that has been hitherto distinguished by the name of philosophy are the most fitted for the apprehension of truth.”

57. “Few look for truth; many prowl about for a reputation of profundity by arrogantly challenging whichever arguments are the best.”

58. “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.”

59. “The entire method consists in the order and arrangement of the things to which the mind’s eye must turn so that we can discover some truth.”

60. “I concluded that I might take as a general rule the principle that all things which we very clearly and obviously conceive are true; only observing, however, that there is some difficulty in rightly determining the objects which we distinctly conceive.”

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

62. “There is nothing more ancient than the truth.”

63. “But possibly, I am something more than I suppose myself to be.”

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

65. “It is best not to go on for great quest for truth, it will only make you miserable.”

René Descartes Quotes That Will Tell You More About the Mind and Critical Thinking

66. “Intuition is the undoubting conception of a pure and attentive mind, which arises from the light of reason alone, and is more certain than deduction.”

67. “Now, therefore, that my mind is free from all cares, and that I have obtained for myself assured leisure in peaceful solitude, I shall apply myself seriously and freely to the general destruction of all my former opinions.”

68. “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.”

69. “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.”

70. “I did not imitate the skeptics who doubt only for doubting’s sake, and pretend to be always undecided; on the contrary, my whole intention was to arrive at a certainty and to dig away the drift and the sand until I reached the rock or the clay beneath.”

71. “We call infinite that thing whose limits we have not perceived, and so by that word we do not signify what we understand about a thing, but rather what we do not understand.”

72. “There is a little gland in the brain in which the soul exercises its functions in a more particular way than in the other parts.”

73. “Human wisdom remains always one and the same although applied to the most diverse objects and it is no more changed by their diversity than the sunshine is changed by the variety of objects which it illuminates.”

74. “If I go for the alternative which is false, then obviously I shall be in error; if I take the other side, then it is by—chance that I arrive at the truth, and I shall still be at fault. In this incorrect use of free will may be found the privation which constitutes the essence of error.”

75. “For each of us there is a set limit to our intellectual powers which we cannot pass.”

76. “The mind effortlessly and automatically takes in new ideas, which remain in limbo until verified or rejected by conscious, rational analysis.”

77. “Those who travel very slowly may yet make far greater progress, provided they keep always to the straight road than those who, while they run, forsake it.”

78. “Although my knowledge grows more and more, nevertheless, I do not for that reason believe that it can ever be actually infinite since it can never reach a point so high that it will be unable to attain any greater increase.”

79. “There is a great difference between mind and body insomuch as body is by nature always divisible, and the mind is entirely indivisible.”

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

Insightful René Descartes Quotes

81. “I was convinced that our beliefs are based much more on custom and example than on any certain knowledge.”

82. “Every man is indeed bound to do what he can to promote the good of others, and a man who is of no use to anyone is strictly worthless.”

83. “Instead I ought to be grateful to Him who never owed me anything for having been so generous to me, rather than think that He deprived me of those things or has taken away from me whatever He did not give me.”

84. “Regard this body as a machine which, having been made by the hand of God, is incomparably better ordered than any machine that can be devised by man, and contains in itself movements more wonderful than those in any machine. It is for all practical purposes impossible for a machine to have enough organs to make it act in all the contingencies of life, in the way in which our reason makes us act.”

85. “And I shall always hold myself more obliged to those by whose favor I enjoy uninterrupted leisure than to any who might offer me the most honorable positions in the world.”

86. “Even those who have the weakest souls could acquire absolute mastery over all their passions if we employed sufficient ingenuity in training and guiding them.”

87. “Traveling is almost like talking with those of other centuries.”

88. “Situations in life often permit no delay; and when we cannot determine the course which is certainly best, we must follow the one which is probably the best. This frame of mind freed me also from the repentance, and remorse commonly felt by those vacillating individuals, who are always seeking worthwhile things which they later judge to be bad.”

89. “It is useful to know something of the manners of different nations, that we may be enabled to form a more correct judgment regarding our own and be prevented from thinking that everything contrary to our customs is ridiculous and irrational, a conclusion usually come to by those whose experience has been limited to their own country.”

90. “I also considered how the same person, with the same mind, who was brought up from infancy either among the French or the Germans, becomes different from what they would have been if they had always lived among the Chinese or among the cannibals.”

91. “So far, I have been a spectator in this theater which is the world, but I am now about to mount the stage, and I come forward masked.”

René Descartes Quotes to Gain More Information on Math and Logical Reasoning

92. “Among all those who up to this time made discoveries in the sciences, it was the mathematicians alone who had been able to arrive at demonstrations.”

93. “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.”

94. “If we possessed a thorough knowledge of all the parts of the seed of any animal, we could from that alone deduce the whole conformation and figure of each of its members.”

95. “Reason is nothing without imagination.”

96. “Neither the true nor the false roots are always real; sometimes they are imaginary; that is, while we can always imagine as many roots for each equation as I have assigned, yet there is not always a definite quantity corresponding to each root we have imagined.”

97. “As I considered the matter carefully it gradually came to light that all those matters only were referred to mathematics in which order and measurements are investigated and that it makes no difference whether it be in numbers, figures, stars, sounds, or any other object that the question of measurement arises. I saw consequently that there must be some general science to explain that element as a whole which gives rise to problems about order and measurement, restricted as these are to no special subject matter. This, I perceived was called ‘universal mathematics.’”

98. “It cannot be denied that he has had many exceptional ideas and that he is a highly intelligent man. For my part, however, I have always been taught to take a broad overview of things, in order to be able to deduce from them general rules, which might be applicable elsewhere.”

99. “I accept no principles of physics which are not also accepted in mathematics.”

100. “Here I beg you to observe in passing that the scruples that prevented ancient writers from using arithmetical terms in geometry, and which can only be a consequence of their inability to perceive clearly the relation between these two subjects, introduced much obscurity and confusion into their explanations.”

101. “It is contrary to reasoning to say that there is a vacuum or space in which there is absolutely nothing.”

102. “It is enough that I can understand one thing, clearly and distinctly, without another in order to be certain that one thing is distinct from the other.”

103. “Mathematics is a more powerful instrument of knowledge than any other that has been bequeathed to us by human agency.”

104. “But in my opinion, all things in nature occur mathematically.”

105. “I paid special attention to Arithmetic and Geometry.”

René Descartes Quotes on Science and Discoveries

106. “Give me extension and motion and I will construct the universe.”

107. “Even the mind depends so much on temperament and the disposition of one’s bodily organs that, if it is possible to find a way to make people generally wiser and more skillful than they have been in the past, I believe that we should look for it in medicine.”

108. “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.”

109. “There is nothing so far removed from us as to be beyond our reach or so hidden that we cannot discover it.”

110. “Archimedes, that he might transport the entire globe—demanded only a point that was firm and immovable; so also, I shall be entitled to entertain the highest expectations, if I am fortunate enough to discover only one thing that is certain and indubitable.”

111. “It is to the body alone that we should attribute everything that can be observed in us to oppose our reason.”

112. “And thereby make ourselves, as it were, the lords and masters of nature.”

113. “I should consider that I know nothing about physics if I were able to explain only how things might be, and were unable to demonstrate that they could not be otherwise.”

114. “The rainbow is such a remarkable phenomenon of nature, and its cause has been so meticulously sought after by inquiring minds throughout the ages, that I could not choose a more appropriate subject for demonstrating how, with the method I am using, we can arrive at knowledge not possessed at all by those whose writings are available to us.”

115. “Science is practical philosophy.”

116. “It is true that medicine, as it is currently practiced, contains little of much use.”

117. “We never understand a thing so well, and make it our own, as when we have discovered it for ourselves.”

118. “If I found any new truths in the sciences, I can say that they follow from, or depend on, five or six principal problems which I succeeded in solving and which I regard as so many battles where the fortunes of war were on my side.”

Deep René Descartes Quotes About Emotions and Sensations 

119. “Gratitude is a species of love, excited in us by some action of the person for whom we have it, and by which we believe that he has done some good to us, or at least that he has had the intention of doing so.”

120. “How do we know that anything really exists, that anything is really the way it seems to us through our senses?”

121. “A person has two passions for love and abhorrence. A big disposition to excessiveness has just love because it is more ardent and stronger.”

122. “The principal use of prudence, of self-control, is that it teaches us to be masters of our passions, and to so control and guide them that the evils which they cause are quite bearable, and that we even derive joy from them all.”

123. “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.”

124. “And as it is the most generous souls who have most gratitude, it is those who have most pride, and who are most base and infirm, who most allow themselves to be carried away by anger and hatred.”

125. “It’s the familiar love-hate syndrome of seduction; ‘I don’t really care what it is I say, I care only that you like it.’”

126. “Just as we believe by faith that the greatest happiness of the next life consists simply in the contemplation of this divine majesty, likewise we experience that we derive the greatest joy of which we are capable in this life from the same contemplation, even though it is much less perfect.”

127. “I am a thing that thinks; that is, a thing that doubts, affirms, denies, understands a few things, is ignorant of many things, is willing, is unwilling, and also which imagines and has sensory perceptions.”

128. “Sensations are nothing but confused modes of thinking.”

René Descartes Quotes on Dreams and Illusions

129. “Even if I were to suppose that I was dreaming and whatever I saw or imagined was false, yet I could not deny that ideas were truly in my mind.”

130. “Hence reason also demands that, since our thoughts cannot all be true because we are not wholly perfect, what truth they do possess must inevitably be found in the thoughts we have when awake, rather than in our dreams.”

131. “How can you be certain that your whole life is not a dream?”

132. “It is possible that I am dreaming right now and that all of my perceptions are false.”

133. “But I cannot forget that at other times I have been deceived in sleep by similar illusions; and, attentively considering those cases, I perceive so clearly that there exist no certain marks by which the state of waking can ever be distinguished from sleep, that I feel greatly astonished; and in amazement, I almost persuade myself that I am now dreaming.”

134. “I suppose therefore that all things I see are illusions; I believe that nothing has ever existed of everything, my lying memory tells me. I think I have no senses. I believe that body, shape, extension, motion, location are functions. What is there then that can be taken as true?”

135. “For how do we know that the thoughts which occur in dreaming are false rather than those others which we experience when awake since the former are often not less vivid and distinct than the latter?”

136. “The dreams we imagine when we are asleep should not in any way make us doubt the truth of the thoughts we have when we are awake.”

137. “Hope is the desire of the soul to be convinced that the dream will come true.”

René Descartes Quotes That Discuss God and Existence

138. “Intuitive knowledge is an illumination of the soul, whereby it beholds in the light of God those things which it pleases Him to reveal to us by a direct impression of divine clearness.”

139. “In God, there is an infinitude of things which I cannot comprehend, nor possibly even reach in any way by thought; for it is the nature of the infinite that my nature, which is finite and limited, should not comprehend it.”

140. “On the one hand, I have a clear and distinct idea of myself, in so far as I am a thinking, non-extended thing; and on the other hand, I have a distinct idea of body, in so far as this is simply an extended, non-thinking thing. And, accordingly, it is certain that I am really distinct from my body, and exist without it.”

141. “Before examining this more carefully and investigating its consequences, I want to dwell for a moment in the contemplation of God, to ponder His attributes in me, to see, admire, and adore the beauty of His boundless light, insofar as my clouded insight allows.”

142. “Neither divine grace nor natural knowledge ever diminishes freedom.”

143. “I experienced in myself a certain capacity for judging which I have doubtless received from God, like all the other things that I possess; and as He could not desire to deceive me, it is clear that He has not given me a faculty that will lead me to err if I use it aright.”

144. “This result could have been achieved either by His 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.”

145. “Be that as it may, there is fixed in my mind a certain opinion of long-standing, namely that there exists a God who is able to do anything and by whom I, such as I am, have been created. How do I know that he did not bring it about that there is no earth at all, no heavens, no extended thing, no shape, no size, no place, and yet bringing it about that all these things appear to me to exist precisely as they do now?”

146. “When writing about transcendental issues, be transcendentally clear.”

147. “I have concluded the evident existence of God, and that my existence depends entirely on God in all the moments of my life, that I do not think that the human spirit may know anything with greater evidence and certitude.”

148. “God alone is the author of all the motions in the world.”

149. “The only secure knowledge is that I exist.”

150. “When I was examining what I was, I realized that I could pretend that I had no body—but I could not pretend in the same way that I did not exist.”

Do You Agree With René Descartes’ Philosophy That All Humans Are Born With Innate Knowledge?

René Descartes invented Analytic Geometry and used metaphysics to prove God’s existence. He also introduced the concept of doubt in solving problems. His contributions to philosophy, science, and mathematics are indeed undeniable.

René Descartes’s method proved to be helpful in any life situation. We hope these lines and quotes were able to encourage you to discover more about life and be skeptical when needed. Maybe you can use them to face your challenges, too!

Life is full of problems that we must solve. Let us use our intelligence to survive in the face of adversity. We hope you learned a thing or two from René Descartes today.

Which of his quotes inspired you to be more vigilant in life? Please, don’t forget to share them in the comments section.

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Karen Danao

Hi, I’m Karen, a content curator and writer for Quote Ambition; I’m also a marketing and advertising professional. Beyond the keyboard and the screen, I’m someone who’s out to enjoy every bit that life has to offer!

Poetry, philosophy, history, and movies are all topics I love writing about! However, my true passion is in traveling, photography, and finding common ground to which everyone from different cultures can relate.

With the many places I’ve been to, I found that love, inspiration, and happiness are some things that bring people together. No matter how different we are on the outside, I’m a true believer that our emotions don’t lie; if you dig deep into our psyche, we’re all the same inside.

This belief was further amplified when I joined Quote Ambition. Through the quotes I’ve read, collected, organized, and written about, I found that humans are resilient, creative, and compassionate.

We take from each others’ hearts and courage, and it’s through our individual experiences that we learn how to rise above our challenges and pain. In so many ways, Quote Ambition is a platform that allows people from all over the world to gain the inspiration they need anytime, anywhere!

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