Discourse on Method and Related Writings

by René Descartes, Desmond M. Clarke (Translator)

‘It is not enough to have a good mind; it is more important to use it well’

René Descartes was a central figure in the scientific revolution of the seventeenth century. In his Discourse on Method he outlined the contrast between mathematics and experimental sciences, and the extent to which each one can achieve certainty. Drawing on his own work in geometry, optics, astronomy and physiology, Descartes developed the hypothetical method that characterizes modern science, and this soon came to replace the traditional techniques derived from Aristotle. Many of Descartes’ most radical ideas – such as the disparity between our perceptions and the realities that cause them – have been highly influential in the development of modern philosophy.

This edition sets the Discourse on Method in the wider context of Descartes’ work, with the Rules for Guiding One’s Intelligence in Searching for the Truth (1628), extracts from The World (1633) and selected letters from 1636–9. A companion volume, Meditations and Other Metaphysical Writings, is also published in Penguin Classics.

Genres: Philosophy, Nonfiction, Classics, Science, 17th Century, France, French Literature

208 pages, Paperback

First published January 1, 1637

About the author

Meditations on First Philosophy (1641) and Principles of Philosophy (1644), main works of French mathematician and scientist René Descartes, considered the father of analytic geometry and the founder of modern rationalism, include the famous dictum "I think, therefore I am."

A set of two perpendicular lines in a plane or three in space intersect at an origin in Cartesian coordinate system. Cartesian coordinate, a member of the set of numbers, distances, locates a point in this system. Cartesian coordinates describe all points of a Cartesian plane.

From given sets, {X} and {Y}, one can construct Cartesian product, a set of all pairs of elements (x, y), such that x belongs to {X} and y belongs to {Y}.

Cartesian philosophers include Antoine Arnauld.



René Descartes, a writer, highly influenced society. People continue to study closely his writings and subsequently responded in the west. He of the key figures in the revolution also apparently influenced the named coordinate system, used in planes and algebra.

Descartes frequently sets his views apart from those of his predecessors. In the opening section of the Passions of the Soul , a treatise on the early version of now commonly called emotions, he goes so far to assert that he writes on his topic "as if no one had written on these matters before." Many elements in late Aristotelianism, the revived Stoicism of the 16th century, or earlier like Saint Augustine of Hippo provide precedents. Naturally, he differs from the schools on two major points: He rejects corporeal substance into matter and form and any appeal to divine or natural ends in explaining natural phenomena. In his theology, he insists on the absolute freedom of act of creation of God.

Baruch Spinoza and Baron Gottfried Wilhelm von Leibniz later advocated Descartes, a major figure in 17th century Continent, and the empiricist school of thought, consisting of Thomas Hobbes, John Locke, George Berkeley, and David Hume, opposed him. Leibniz and Descartes, all well versed like Spinoza, contributed greatly. Descartes, the crucial bridge with algebra, invented the coordinate system and calculus. Reflections of Descartes on mind and mechanism began the strain of western thought; much later, the invention of the electronic computer and the possibility of machine intelligence impelled this thought, which blossomed into the Turing test and related thought. His stated most in §7 of part I and in part IV of Discourse on the Method .

Reviews

[Riku Sayuj · Rating 3 out of 5]

Descartes probably had the best questions ever and the worst answers ever.

Questions: How can I know if reality is as I perceive it? If I exist? If God exists?

Answers: I can think, hence my mind exists, hence I exist. I can think of a god hence God exists. God must be good. A good God wouldn't fool me. So reality exists as I perceive it.

[E. G. · Rating 3 out of 5]

Acknowledgements
Note on References to Descartes
Chronology
Introduction
Further Reading

Note on the Text and Translation
--Discourse on the Method for Guiding One's Reason and Searching for Truth in the Sciences

--Selected Correspondence, 1636-9

Note on the Text
--The World, or a Treatise on Light and the Other Principal Objects of the Senses (Chapters 1-7)

Note on the Text
--Rules for Guiding One's Intelligence in Searching for the Truth

Text Notes
Index

[Nitin Shukla · Rating 5 out of 5]

A must read and something which was written in 17th century to be still valid says it all.
There are so many fundamental things being spoken in this text that i've never seen any one else writing. Quite thorough and at the same time to the point.

[Sookie]

Much of the content repeats and repeats and repeats. Maybe its the edition that I own that has the problem, but overall it wasn't an enjoyable read, in the way collection was put together. The reason why I picked up this book was primarily how Descartes lays out rules for rational thought process and how to problem solve. Descartes was a great mathematician and its fascinating to read his philosophical point of view in the way he looked at mathematics and arrived at solutions. It becomes a little muddled when the rules for intelligence shift to second half of the book. I think, therefore I am is his most well known phrase which acts as a setting to some of the claims he makes as an enlightened man.

[Bloom Rash · Rating 5 out of 5]

The history of philosophy has not been the same since Descartes. It is hard to underscore the impact this tiny little book has had on the trajectory of thought. While it was intended to be written in common language (French instead of “scholarly” Latin)) it is still can be quite hard for newcomers, but I recommend nonetheless.

[Zoir · Rating 4 out of 5]

Discourse on Method was a solid intro to kick off my dive into Western philosophical thought. The dude did the whole "I think, therefore I am" thing, going back to basics and questioning everything--gotta respect that. Feels like a teaser leading up to his Meditations. I can see why so many see him as the father of modern philosophy.

The Meditations are where the boy really goes off the rails--tryna prove God’s existence and that our souls are immortal, while basically reinventing reality from scratch. It's ambitious as hell, but kinda crazy how much he leans on God as the ultimate guarantee for truth. He doubts literally everything else, but when it comes to God, he's just like, "Nah, this one's no cap." Some of the logic feels like it's twisting around itself just to make it fit, but honestly, I respect the hustle.

[Dave B. · Rating 3 out of 5]

Descartes is enjoyable as a rationalist philosopher. I throughly embrace his ideals of self reflection and learning. My only problem is an issue that is core to most rationalist argument up to the 19th century. All analysis and argumentation relies on the existance of God. So every argument ends with the essential statement "Argument A is so because God wants it so". This is not to imply I don't have faith in God. I just believe that a rational logical argumentation must center around observable fact not assumed faith. This opinion doesn't translate to the idea that Descartes is not worth the time reading. He is listed as one of the greatest minds of western society for a reason. To read his works is to understand core ideas held by the western mind.

[rollie · Rating 2 out of 5]

storygraph

(reviewed 2026-03-12)

i picked this up when i was having a nonfiction moment...... and tbh i dont think i was quite ready for this book LOL -- so this review is more of a reflection on my own reading experience rather than the work itself.

i found this book overall a touch incomprehensible LMFAO (probably made worse by how long it took me to get through the last 50 pages)... and could not really figure out if it was bc of my own comprehension skills, the translation, or descartes being a yapper... but upon skimming the book to write this review, i think it's a mix of:

1.   my lack of familiarity with the philosophy + methods that descartes uses to explain his ideas
2.   the translator being very thoughtful, nuanced, and thorough despite descartes being rambly as hellllll LOL
3.   descartes being a guy who prefaces and over-qualifies his statements too much before getting to the point/while getting to the point... (but maybe this is his method... see issue 1 lmfao.)

that said! maybe one day this will get a reread from me... i can appreciate the earlier sections more in hindsight (after reading 'the rules'). and my shallow, plebeian thoughts on the sections, in brief:

●   discourse: i quite resonated with this overall! (in how to explain yourself accurately and have others receive what you communicated as you intended.) but oh man to anyone who thinks they pre-qualify their statements too much (myself included)... u have yet to meet rene descartes final boss lmao
●   selected correspondences: i'll never not find personal correspondences to one's contemporaries not interesting to read. i think i wouldve hated texting descartes (very formal, walls of text, a bit overly self-deprecating in that uncomfortable to watch way)
●   the world: tbqh i forget that i even read this section lol. upon a re-skim this reminds me that it was around here where i started to get a lot of "it came to me in a dream" vibes.
●   rules: lowkey a heruclean reading effort to get through this, on my part lmao,,, genuinely i found the text so incomprehensible sometimes LOL like... where tf was the sentence going... how did we end up here.... shoutout to the footnotes. (i think it was a me issue more than anything.)
●   the footnotes: special shoutout to these. i always laughed when there was a footnote for some mysterious phrase descartes used only for the footnote to briefly explain its reference to some philosophical/renaissance era idea that i had no prior familiarity with...

the verdict:

"Besides, the habit [people] will acquire by searching initially for easy things and moving gradually to more difficult ones will be more useful to them than all my instructions. Just as, for my own part, I am convinced... if I had learned [the truths from my youth] without effort, I might never have known any others; at least, I would never have acquired the habit and facility that I think I have for always finding new truths as I apply myself to search for them." (Discourse on Method, pt 6)

this was a hard read for me as someone who picked this up mostly for funsies... not sure how much will stick with me LMAO. my enthusiasm definitely started to fade by the end of this lmao but if anything, i think the most memorable (as i go through my notes) was descartes' descriptions of needing to slowly grapple with your thoughts/ideas to understand them (and the world) fully... what a refreshing sentiment in this day and age lol where it feels like the world is actively working to smooth my brain out.

===

post-read: oh god finally lmao. maybe like a 2.5. rtc

[Nicholas · Rating 3 out of 5]

"This is not the greatest method in the world, no
This is just a tribute..."
-Tenacious D(escartes)

***

Genitor of Descartes' most famous quote "I think, therefore I am", the remainder of the Discourse itself is surprisingly slight. I think that the questions and method itself is often fascinating, and the conclusions that he states are true (e.g. that God exists), but don't think he convincingly shows enough working to prove that the method is able to produce the answer. It is also clear, as the notes explain, that the Discourse was written as a hastily rushed 'afterthought' to introduce his collection of essays, which aren't actually included in the volume. (Of the 6 parts, most of the fifth is a description of the circular system which seems to have no relevance to the rest haha)

However, Descartes' incomplete Rules for Guiding One's Intelligence in Searching for the Truth in which he only wrote 18 of the intended 36 rules (and 3 more in part), which is included, is almost more fascinating as his attempt to write down a full treatise of his method. It is interesting to see the overlap of his mathematical persuasion with his philosophical method, as he breaks down questions into solvable components and builds knowledge from root concepts into more complex forms. The final few rules use descriptions of algebraic conventions to explain his philosophical process

Read this as a precursor to Meditations... which I plan to read for Pewdiepie's 2025 challenge haha

[Sam Sasaki · Rating 4 out of 5]

“For since God has given each of us a light for distinguishing what is true from what is false, I could not have believed that I should be content with the views of other people for a single moment if I had not planned to use my own judgement to examine them in due course, and I could not have avoided having scruples about their opinions if I had not hoped thereby not to miss any opportunity to find better ones if such were available. I would not have been able to limit my desire or to be satisfied if I had not followed a path by which, thinking I was certain to acquire all the knowledge of which am capable, I also thought I could acquire all the genuine goods that would ever be within my grasp. For since our will cannot follow or flee from anything except in so far as our understanding represents the thing in question as good or evil, judging well is enough to do good, and judging as well as possible is enough to do one's best, that is, to acquire all the virtues and, with them, all the other goods that one is capable of acquiring. When someone is certain of this, they cannot fail to be satisfied.”

[Paul Spencer · Rating 4 out of 5]

If anyone doubts that Descartes is the godfather of all modern scientific enterprise, read this. He was the first to reform science to rely, at a fundamental/theoretical level, on math. Descartes posited that there is a distinct divide between mind and material, and our mind works better when we assume that it is divorced from the world at the point of our untrustworthy senses. We must trust math instead of direct observation.

We've seen how well Descartes' method works in verifying material concerns (see quantum theory and relativity). Further, we now believe in matter as the trustworthy thing, not mind (if mind even exists beyond material), the implications of which contribute significantly to the despondency of our era.

But anyone who wants to blame Descartes for the modern meaning crisis would do well to revisit his first 2 conclusions upon which his mathematical explanations hang and without which they are meaningless. I am mind and God exists. Nothing without these. The math is unanchored meaninglessness without mind and God.

[Maris C · Rating 4 out of 5]

A good introduction to Descartes' philosophy. Overall I enjoyed it, although I found Descartes to be inconsistent. He outlines a method he alleges will allow people to discover capital t Truths, and then proceeds to not actually follow the method. For example, the first rule of the method is to never accept anything as true if you do not know clearly and distinctly that it is so beyond doubt. This involves questioning widely accepted beliefs and even things established as truth by academics. He then goes on to support his belief that God made nature by saying it's"a view that is widely accepted among theologians" and justifies other opinions in similar ways. It's kind of frustrating to read. Can bro really not see the hypocrisy in his argument? People should question authority but never the Church.

Despite the crippling effect this refusal to seriously question Catholicism has on his argument, Descartes still has something to offer readers today. The Discourse is written in a clear and extremely straightforward way by philosophical standards. It was easier to get through than I expected and I am interested in reading the Meditations too, if only to become a better thinker myself by determining where his arguments fall through.

[Ian · Rating 4 out of 5]

I’ve mostly heard bad things about Descartes and his philosophy, and while I am not rationalist, or believer in God, I enjoyed “the method.” The first three and final sections are great; the rest are very presumptuous, but the particulars (there must be God and soul) do not take from the overall significance.

Descartes exhibits a sense of childlike wonder which he channels into a desire for discovery and maturity. This is a mindset very close to my own, even if my modern conclusions are different. He tries to start from the beginning and be clear and open minded about how he proceeds — while criticizing popular dogmatic thought — even if some of it (eg that the existence of god must be so) is more convenient than reasonable.

[Håvard Bamle · Rating 4 out of 5]

Symbolic rating. I don't agree with the argument, and the reasoning is thin, but the work is undeniably foundational to modern philosophy and influential to many later theories that are worth taking serioysly.


The book is mainly a narrative, relating Descartes conclusions about Knowledge, The soul, God, Man and animals, without laying out the arguments preceding these conclusions (I suppose the main argument is laid out in Meditations on first Philosophy?), making Discourse on Method an accessible read to anyone.

[Damian · Rating 1 out of 5]

Many might disagree, but I would recomend this book to nobody. If Descartes was genious, it escaped me.
I remember looking at greatness and not understanding it, case and point the Karpov vs. Kasparov chess matches of years back. Descartes .... not the case.

[madison bradford · Rating 3 out of 5]

western political thought II

[katelyn ♡ · Rating 2 out of 5]

this guy is not fun at parties

[David · Rating 4 out of 5]

This book combines Descartes famous Discourse on Method along with some polite correspondence letters written to its critics, as well as two other publications: Rules for Guiding One's Intelligence in Searching for the Truth and a portion of The World.

The Discourse on Method itself is a must-read for students of philosophy, mathematics or any of the sciences (especially engineering or computer science), as it defines indispensable ground rules for problem-solving. He establishes some basic rules now common to engineering, such as, never accepting something to be true unless you know it to be true, dividing a problem into as many smaller manageable pieces as necessary to resolve it efficiently, attacking all the pieces of a problem at the simplest pieces first, and to meticulously document/enumerate the processes and solution as you go. The latter portions of this discourse focus on the philosophical question of man's most irreducible elements, searching for a definition of the soul. From this portion you get the famous phrase "I think therefore I am".

The excerpts from The World, were not terribly interesting, but this owes more to the fact that it is severely dated. There were some portions of it that lightly referenced the heliocentric theory which caused Descartes to hold off publication until after his death, once he saw how the church reacted to Galileo's publications. But again, many of the postulations are dated and based on a 17th century view of matter, physiology, and astronomy.

The Rules for Guiding One's Intelligence in Searching for the Truth can be thought of as an detailed extension of the techniques outlined in Discourse on Method and is perhaps much more suited to students or professionals whose line of work requires day-to-day implementation of the scientific method. His view is that "mathematical studies" should be more than just the narrow categorization in which we've come to see arithmetic and geometry. Instead it should imply any study or technique that deals with order or measure, regardless if it deals with numbers, figures, stars, sounds or something else. He felt that this broader definition is what was understood by the Greeks who studied under Pythagoras & Plato, who had prerequisite for any potential student to have an understanding of "mathesis". He enumerates twenty-one rules that constitute this understanding of mathematical practice, much of which is now the basis of the modern scientific method, specifically related to defining and developing a hypothesis. It is incredibly useful publication that I can see myself coming back to and re-reading often in the future.

[Eric Rupert · Rating 1 out of 5]

It is very difficult for me to understand how this preface to his essays on Dioptrics, Meteors, and Geometry can be seen as anything more than a series of egotistical rationalizations based upon errors not of the senses but of the sense of self. Surely the science that Descartes accomplished in his lifetime was revolutionary if not simply a part of the vast revolution in science that was occurring at the time, but his Discourse on Method (that is, his scientific method) can be summarized in four pages instead of the forty that he wrote. Here is science writing in need of an editor.

Some of the claims he makes sound completely paranoid, such as his fears that his work is so important that he can't afford the time to publish it because of the time it will take him to explain his work to all of the common idiots who will surely question it. And his fears about spending too much time reveling in the fame his work would surely bring him. But it is his conclusion that God exists because perfection must exist (what else could he have said during this final Inquisitional phase in history anyway) that leaves me the most baffled.

"I think, therefore I am" is a far more poetically applied aphorism for this work than the its true nature: My ego exists, therefore I am too important to matter to the likes of you.

Of course, Descartes would say that I don't like it because I don't understand it. But I would counter by saying that I understand his points about how to begin a scientific or philosophical journey. It's all the extraneous paranoid narcissistic nonsense that needs explaining.

[Ben · Rating 3 out of 5]

Descartes was so much more than cogito ergo sum, the realized existence theory that is bashed into our brains by countless Philosophy 101 professors and teachers at the moment of our birth into (facilitated) critical thinking, and this text of his collected works proves his effective (while dated) means of looking at life and thought through the lens of a mathematic and scientific method. Though no longer widely accepted in contemporary philosophy, one has to appreciate, if not entirely admire, Descartes's dedication and discipline in achieving enlightenment through himself, not through the world around him. A supremely modern text, his "Methods.." in particular allows us to see where we were and how far we have come in philosophy, and furthermore provide us with a means -and method- to question our existence, morality, and most of all, where we seek and arrive at conclusions concerning what is rightfully true.

[Edmond · Rating 4 out of 5]

« Je pense, donc je suis » “I think, therefore I am.” Reading Descartes, one can see the foundations for the modern atheistic ideology, rationalism is scepticism. The scientific method keeps the rationalist, sceptic from falling into total agnosticism and scepticism. Modern man over rated the scientific method, he can not see the limits to the scientific method. Reading a rationalist like Descartes, one can see the superior nature of mystical thought. Alas, a rationalist can not see the limits of reason.

[Rizal Nova Mujahid · Rating 4 out of 5]

“Seperti menyelesaikan teka-teki matematika,” begitulah komentarku pada teman yang juga membaca buku ini.
“Apanya yang kayak matematika?” Tanya teman yang kebetulan dari Fakultas Ilmu Komputer
“Puyengnya,” jawabku. “Dan gak pernah tau, kenapa kok tiba-tiba selese, dan kok selesenya seperti ini?”
Lalu kami tertawa. Dan syukurlah, sampai saat ini, buku ini hanya selesai dibaca, beberapa kali malah, dan tetep, gak ngerti apa maksudnya.

[Angela Randall]

Free audiobook available (in English) here

[em🪐 · Rating 1 out of 5]

ti odio muori sparati

[Nicolas Souleles · Rating 5 out of 5]

René Descartes: A Discourse on Method and Related Writings
Published by: Penguin Classics

The Discourse on Method is a very short work (60 pages or so) and was intended initially to preface Descartes three scientific essays. The publishers of this edition thus included a collection of other works by Descartes as well as various correspondences all selected to provide context for the work.

Discourse on Method: The Discourse itself is just that, a discourse. It was never intended to be a comprehensive account of Descartes’ philosophy and it does no such thing. The work is more anecdotal in nature, providing a personal account of the development of Descartes’ skepticism (the philosophical idea) and his application. It then proceeds to discuss the results of the application of his skepticism in the discussion of how it relates to his physics and what that implied for his religeon. He also advocates for the use of inductive reasoning rather than deductive reasoning (reasoning from evidence rather than reasoning from first principles/axiomatically) and diverged from the use of Aristotelian “demonstrations”, which employed the latter form of logic, in the discussion of the natural world. As is expected Descartes got some things wrong about the world, like his contention that the action of the heart was due to heat expansion, but he also got a lot of things right and contributed greatly to what is now the method of science.

Selected Correspondances: There are a number of correspondences which serve to provide a little context for the Discourse as well as a look into how it was seen by his contemporaries.

The World: This book provides a short depiction of what an imaginary world might look like given Descartes understanding of the laws of physics. As far as I am aware, he opted to describe an imaginary world rather than the real world partially out of fear of what had happened to Galileo. It was for this reason he never published his comprehensive physics and this book was published posthumously.

Rules for Guiding one's Intelligence in Searching for the Truth: This work was also never published in Descartes’ lifetime. It is as its name suggests: a list of rules, and it outlines a method for finding truth. It was a precursor to the Discourse on Method written afterwards, and one can see how the philosophy of skepticism could have been developed by its author. This work is more assertive than the Discourse, but it still advises diligence and caution in finding the truth and suggests that the properties of objects should be determined from what we can observe; though Descartes focuses on empiricism a little more in the Discourse and the Rules are a little more abstract.

I recommend this book to anyone who is interested in philosophy, and I look forward to rereading it myself so that I can understand it better.