Editing Cogito, ergo sum (section)

== In Descartes's writings ==
Descartes first wrote the phrase in French in his 1637 ''[[Discourse on the Method]]''. He referred to it in Latin without explicitly stating the familiar form of the phrase in his 1641 ''[[Meditations on First Philosophy]]''. The earliest written record of the phrase in Latin is in his 1644 ''[[Principles of Philosophy]]'', where, in a margin note (see below), he provides a clear explanation of his intent: "[W]e cannot doubt of our existence while we doubt". Fuller forms of the phrase are attributable to other authors.

=== ''Discourse on the Method'' ===
The phrase first appeared (in French) in Descartes's 1637 ''[[Discourse on the Method]]'' in the first paragraph of its fourth part:

{{Verse translation|{{lang|fr|Ainsi, à cause que nos sens nous trompent quelquefois, je voulus supposer qu'il n'y avait aucune chose qui fût telle qu'ils nous la font imaginer; Et parce qu'il y a des hommes qui se méprennent en raisonnant, même touchant les plus simples matières de Géométrie, et y font des Paralogismes, jugeant que j'étais sujet à faillir autant qu'aucun autre, je rejetai comme fausses toutes les raisons que j'avais prises auparavant pour Démonstrations; Et enfin, considérant que toutes les mêmes pensées que nous avons étant éveillés nous peuvent aussi venir quand nous dormons, sans qu'il y en ait aucune raison pour lors qui soit vraie, je me résolus de feindre que toutes les choses qui m'étaient jamais entrées en l'esprit n'étaient non plus vraies que les illusions de mes songes. Mais aussitôt après je pris garde que, pendant que je voulais ainsi penser que tout était faux, il fallait nécessairement que moi qui le pensais fusse quelque chose; Et remarquant que cette vérité, '''''{{nowrap|je pense,}} {{nowrap|donc je suis}}''''',{{efn|name="formatting"}} était si ferme et si assurée, que toutes les plus extravagantes suppositions des Sceptiques n'étaient pas capables de l'ébranler, je jugeai que je pouvais la recevoir sans scrupule pour le premier principe de la Philosophie que je cherchais.|italic=unset}}{{efn|name="formatting2"|Capitalization as in original; spelling updated from [[Middle French]] to [[Modern French]].}}{{efn|1=See original ''Discours'' manuscript [https://gallica.bnf.fr/ark:/12148/btv1b86069594/f37.item.zoom here].}}|Accordingly, seeing that our senses sometimes deceive us, I was willing to suppose that there existed nothing really such as they presented to us; And because some men err in reasoning, and fall into [[:wiktionary:paralogism|Paralogisms]], even on the simplest matters of Geometry, I, convinced that I was as open to error as any other, rejected as false all the reasonings I had hitherto taken for Demonstrations; And finally, when I considered that the very same thoughts (presentations) which we experience when awake may also be experienced when we are asleep, while there is at that time not one of them true, I supposed that all the objects (presentations) that had ever entered into my mind when awake, had in them no more truth than the illusions of my dreams. But immediately upon this I observed that, whilst I thus wished to think that all was false, it was absolutely necessary that I, who thus thought, should be something; And as I observed that this truth, '''''{{nowrap|I think,}} {{nowrap|therefore I am}}''''',{{efn|name="formatting"}} was so certain and of such evidence that no ground of doubt, however extravagant, could be alleged by the Sceptics capable of shaking it, I concluded that I might, without scruple, accept it as the [[first principle]] of the philosophy of which I was in search.{{efn|This translation, by Veitch in 1850,<ref name="Veitch1850">{{cite book | author=Veitch, John | title=Discourse on the Method of Rightly Conducting the Reason, and Seeking Truth in the Sciences, by Descartes | publisher=Sutherland and Knox | year=1850 | location=Edinburgh | pages=74–5 | url = https://archive.org/stream/Descartes1637DiscourseOnTheMethodTrVeitch1850/Descartes%201637%20Discourse%20tr%20Veitch%201850#page/n77/mode/2up/search/Therefore+I+am| author-link=John Veitch (poet) }}</ref> is modified here as follows: Veitch's "I think, hence I am" is changed to the form by which it is currently best known in English, "I think, therefore I am", which appeared in the Haldane and Ross 1911 translation,{{r|Haldane1911|p=100}} and as an isolated attributed phrase previously, e.g., in Sullivan (1794);<ref name=Sullivan1794>{{cite book | author=Richard Joseph Sullivan | title=A View of Nature, in Letters to a Traveller among the Alps, with Reflections on Atheistical Philosophy now exemplified in France | year = 1794 | page=129 | url=https://books.google.com/books?id=1q00AAAAMAAJ&pg=PA129 | publisher=printed for T. Becket | location=London| author-link=Richard Joseph Sullivan }}</ref> in the preceding line, Veitch's "I, who thus thought, should be somewhat" is given here as "… should be something" for clarity (in accord with other translations, e.g., that of Cress<ref name=Cress1986 />); and capitalization was reverted to conform to Descartes's original in French.}}{{efn|The 1637 ''Discours'' was translated to Latin in the 1644 ''Specimina Philosophiae''<ref name="Descartes1644Specimina">{{cite book|author=Descartes, René | title=Specimina philosophiae|publisher=Ludovicus Elzevirius |url=https://archive.org/details/ita-bnc-mag-00001403-001|page=[https://archive.org/details/ita-bnc-mag-00001403-001/page/n68 30] |year=1644}}</ref> but this is not referenced here because of issues raised regarding translation quality.<ref name="Vermeulen2006">{{cite journal|author=Vermeulen, Corinna Lucia|title=René Descartes, ''Specimina philosophiae''. Introduction and Critical Edition|journal=Quaestiones Infinitae|url= https://dspace.library.uu.nl/handle/1874/23451|year=2006|volume=53|hdl=1874/23451|type=Dissertation, Utrecht University}}</ref>}}}}

=== ''Meditations on First Philosophy'' ===
In 1641, Descartes published (in Latin) ''[[Meditations on first philosophy]]'' in which he referred to the proposition, though not explicitly as "cogito, ergo sum" in Meditation II:

{{Verse translation|{{lang|la|hoc pronuntiatum: '''Ego sum, Ego existo''',{{efn|name="formatting3"|''Cogito'' variant highlighted to facilitate comparison; capitalization as in original.}} quoties a me profertur, vel mente concipitur, necessario esse verum.<ref name="Descartes1641">{{Cite book |last=Descartes |first=René |url=https://books.google.com/books?id=R41XAAAAcAAJ |title=Meditationes de prima philosophia, in qua Dei existentia et animae immortalitas demonstratur |date=1641 |publisher=Apud Michaelem Soly |pages=359 |language=la}}</ref>|italic=unset}}|this proposition: '''I am, I exist''',{{efn|name="formatting3"}} whenever it is uttered by me, or conceived by the mind, necessarily is true.{{efn|This combines, for clarity and to retain phrase ordering, the Cress<ref name=Cress1986 /> and Haldane<ref name="Haldane1911">{{cite book|author=Descartes, René | title=The Philosophical Works of Descartes, rendered into English|url=https://archive.org/details/philosophicalwor01desc |others=Translated by Elizabeth S. Haldane and G.R.T. Ross| publisher=Cambridge University Press | year=1911}}</ref>{{rp|150}} translations.}}{{efn|Jaako Hintikka comments that ''ego sum, ego existo'' is the simplest example of an "existentially self-verifying" sentence, i.e., one whose negation verifies itself "when … expressly uttered or otherwise professed"; and that ''ego sum'' is an alternative to ''cogito, ergo sum'' to express "the existential inconsistency of the sentence 'I don't exist' and the existential self-verifiability of 'I exist'".<ref name=Hintikka />}}}}

In Response to an Objection from [[Marin Mersenne]], he wrote "cogito, ergo sum” in an extended form and, again, prefaced with ‘ego’:

{{Verse translation|{{lang|la|Cum advertimus nos esse res cogitantes, prima quædam notio est quæ ex nullo syllogismo concluditur; neque etiam cum quis dicit ‘'''ego cogito, ergo sum, sive existo''',’{{efn|name="formatting3"|''Cogito'' variant highlighted to facilitate comparison; capitalization as in original.}} existentiam ex cogitatione per syllogismum deducit, sed tanquam rem per se notam simplici mentis intuitu agnoscit.{{sfn|Descartes|1641|p=189}}|italic=unset}}|And when we become aware that we are thinking things, this is a primary notion which is not derived by means of any syllogism. When someone says ''''I am thinking, therefore I am, or I exist'''’{{efn|name="formatting3"}} 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.<ref>{{Cite book |last=Cottingham |first=John |url=https://books.google.com/books?id=Q5P2lFaM8GgC&printsec=frontcover&dq=The+Philosophical+Writings+of+DESCARTES+translated+by+JOHN+COTTINGHAM+ROBERTSTOOTHOFF+DUGALD+MURDOCH+%22volume+2%22&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwiy3tLx9byKAxVlNzQIHRsyLn8Q6AF6BAgGEAI#v=onepage&q&f=false |title=The Philosophical Writings of Descartes |last2=Stoothoff |first2=Robert |last3=Murdoch |first3=Dugald |publisher=Cambridge University Press |year=1984 |isbn=978-0-521-28808-8 |pages=71 |language=en}}</ref>}}

=== ''Principles of Philosophy'' ===
In 1644, Descartes published (in Latin) his ''[[Principles of Philosophy]]'' which begins {{lang|la|Veritatem inquirenti semel in vita da omnibus, quantum fieri potest, esse dubitandum.}} (That in order to seek truth, it is necessary once in the course of our life, to doubt, as far as possible, of all things.{{efn|name="GutPrinc4391"}}) The phrase "ego cogito, ergo sum" appears in Part 1, article 7:[[File:1644_Principia_Philosophae.jpg|thumb|"ego cogito, ergo sum" with margin note in original (1644) Principia Philosophae]]{{Verse translation|{{lang|la|Sic autem rejicientes illa omnia, de quibus aliquo modo possumus dubitare, ac etiam, falsa esse fingentes, facilè quidem, supponimus nullum esse Deum, nullum coelum, nulla corpora; nosque etiam ipsos, non habere manus, nec pedes, nec denique ullum corpus, non autem ideò nos qui talia cogitamus nihil esse: repugnat enim ut putemus id quod cogitat eo ipso tempore quo cogitat non existere. Ac proinde haec cognitio, '''''ego cogito, ergo sum''''',{{efn|name="formatting"}} est omnium prima & certissima, quae cuilibet ordine philosophanti occurrat.|italic=unset}}{{efn|1=See original ''Principia'' manuscript [https://books.google.com/books?id=nHBTAAAAcAAJ&pg=PA3&q=%22ego%20cogito%22 here].}}|While we thus reject all of which we can entertain the smallest doubt, and even imagine that it is false, we easily indeed suppose that there is neither God, nor sky, nor bodies, and that we ourselves even have neither hands nor feet, nor, finally, a body; but we cannot in the same way suppose that we are not while we doubt of the truth of these things; for there is a repugnance in conceiving that what thinks does not exist at the very time when it thinks. Accordingly, the knowledge,{{efn|A 1647 French translation,<ref>{{cite book | author=Descartes | title=Principes de la philosophie | year=1647 | translator-first=Abbé Claude | translator-last=Picot | location=Paris| url = https://books.google.com/books?id=C7r-GKWF2xoC&q=abbe+Claude+Picot| isbn=9782711622313 }}</ref> published with Descartes's enthusiastic approval, substituted 'conclusion' for 'knowledge'.<ref>{{cite book | first1 =Valentine Roger | last1 = Miller | first2 = Reese P. | last2 = Miller | title = Descartes, René. Principles of Philosophy. Translated, with explanatory notes | year = 1983 | isbn = 978-90-277-1754-2 | pages = xi,5| publisher = Springer }}</ref>}} '''''I think, therefore I am''''',{{efn|name="formatting"}} is the first and most certain that occurs to one who philosophizes orderly.{{efn|name="GutPrinc4391"}}}}
Descartes's [[marginalia|margin note]] for the above paragraph is:

{{Verse translation|{{lang|la|Non posse à nobis dubitari, quin existamus dum dubitamus; atque hoc esse primum, quod ordine philosophando cognoscimus.|italic=unset}}|That we cannot doubt of our existence while we doubt, and that this is the first knowledge we acquire when we philosophize in order.{{efn|name="GutPrinc4391"}}}}

=== ''The Search for Truth by Natural Light'' ===
Descartes, in a lesser-known posthumously published work written ca. 1647,<ref>{{Citation | last = Gouhier | first = Henri | author-link = Henri Gouhier | title = ''La pensée religieuse de Descartes'' | year = 1924 | page = 319 | url = https://books.google.com/books?id=8Dw1AAAAIAAJ&pg=PA319}}</ref> originally in French with the title {{lang|fr|La Recherche de la Vérité par La Lumiere Naturale}} (''[[The Search for Truth by Natural Light]]'')<ref name="AT" /> and later in Latin with the title {{Lang|la|Inquisitio Veritatis per Lumen Naturale}},<ref>{{Cite book |last=Descartes |first=René |url=https://books.google.com/books?id=XDBnAAAAcAAJ&q=%22dubito%2C+ergo%22&pg=RA2-PP1 |title=Renati Des-Cartes Mvsicae compendivm |date=1683 |publisher=ex typogr. Blauiana |language=la}}</ref> provides his only known phrasing of '''the cogito''' as {{lang|la|'''cogito, ergo sum'''}} and admits that his insight is also expressible as '''''dubito, ergo sum''''':<ref name="Hintikka"/>
[[File:Dubito,_ergo_sum.jpg|thumb|"dubito, ergo sum, vel, quod idem est, cogito, ergo sum" in ''Inquisitio Veritatis per Lumen Naturale'']]
{{Verse translation|{{lang|la|... [S]entio, oportere, ut quid dubitatio, quid cogitatio, quid exsistentia sit antè sciamus, quàm de veritate hujus ratiocinii: '''''dubito, ergo sum''''', vel, quod idem est, '''''cogito, ergo sum'''''{{efn|name="formatting"}} : plane simus persuasi.|italic=unset}}|… [I feel that] it is necessary to know what doubt is, and what thought is, [what existence is], before we can be fully persuaded of this reasoning — '''''I doubt, therefore I am''''' — or what is the same — '''''I think, therefore I am'''''.{{efn|Translation by Hallam,<ref>{{Citation | last = Hallam | first = Henry | title = Introduction to the Literature of Europe in the 15th, 16th, and 17th Centuries | volume = II | edition = 2nd | page = 451 | year = 1843 | url = https://books.google.com/books?id=M4dZUnDvc1kC&q=%22%27%27%27%27%27I+doubt,+therefore+I+am%27%27%27%27%27,+or+what+is+the+same,+%27%27%27%27%27I+think,+therefore+I+am%27%27%27%27%27,+%22&pg=PA451}}</ref> with additions for completeness.}}}}

=== "{{Lang|la|ego cogito, ergo sum}}" or "{{Lang|la|cogito, ergo sum}}"? ===
Peter J. Markie notes: "Descartes stresses the first person in his premise twice in the Principles and once in his Reply to Mersenne. {{Lang|la|ego cogito, ergo sum}} . . . . (AT VIII, 7; AT VIII, 8; AT VII, 140)" and adds "It is unlikely that Descartes would stress the first person in his premise, if he wanted us to read the premise as 'Thought is taking place' rather than 'I think.'"<ref>{{Cite journal |last=Markie |first=Peter J. |date=1982 |title=The Cogito Puzzle |url=https://www.jstor.org/stable/2107513 |journal=Philosophy and Phenomenological Research |volume=43 |issue=1 |pages=79-80 |doi=10.2307/2107513 |issn=0031-8205}}</ref> Gary Hatfield writes: "[I]n Latin the first-person voice need not be expressed through a separate pronoun, but may be included in the verb form; nonetheless, Descartes used the Latin first-person pronoun {{Lang|la|ego}} more than thirty times in the six Meditations."<ref>{{Cite book |last=Hatfield |first=Gary |url=https://www.google.com/books/edition/The_Routledge_Guidebook_to_Descartes_Med/pvEABAAAQBAJ?hl=en&gbpv=1&dq=The+Routledge+Guidebook+to+Descartes%E2%80%99+Meditations&printsec=frontcover |title=The Routledge Guidebook to Descartes' Meditations |date=2014-07-11 |publisher=Routledge |isbn=978-1-317-75485-5 |pages=69 |language=en}}</ref>

=== Other forms ===
The proposition is sometimes given as {{lang|la|dubito, ergo cogito, ergo sum}}. This form was penned by the French literary critic, [[Antoine Léonard Thomas]],{{efn|Thomas was known in his time for his great eloquence especially for éloges in praise of past luminaries.<ref>{{Cite book|last=Stephens|first=Henry Morse|url=https://books.google.com/books?id=SlkyAQAAMAAJ|title=Mirabeau. Vergniaud. Gensonné. Guadet. Louvet. Cambon|date=1892|publisher=Clarendon Press|pages=9|language=fr}}</ref>}} in an award-winning 1765 essay in praise of Descartes, where it appeared as "{{lang|fr|Puisque je doute, je pense; puisque je pense, j'existe}}" ('Since I doubt, I think; since I think, I exist'). With rearrangement and compaction, the passage translates to "I doubt, therefore I think, therefore I am," or in Latin, "''dubito, ergo cogito, ergo sum''."{{efn|The 1765 work, ''Éloge de René Descartes'',<ref name=Thomas1765 /> by Antoine Léonard Thomas, was awarded the 1765 Le Prix De L'académie Française and republished in the 1826 compilation of Descartes's work, ''Oeuvres de Descartes''<ref name=Cousin1824 /> by [[Victor Cousin]]. The French text is available in [http://www.gutenberg.org/files/13846/13846-h/13846-h.htm more accessible format] at Project Gutenberg. The compilation by Cousin is credited with a revival of interest in Descartes.<ref name=Edinburgh1890 /><ref name=Descartes2007 />}} This aptly captures Descartes's intent as expressed in his posthumously published ''La Recherche de la Vérité par La Lumiere Naturale'' as noted above: '''''I doubt, therefore I am''''' — or what is the same — '''''I think, therefore I am'''''.

A further expansion, {{lang|la|dubito, ergo cogito, ergo sum—res cogitans}} ("…—a thinking thing") extends the ''cogito'' with Descartes's statement in the subsequent ''Meditation'', {{lang|la|"Ego sum res cogitans, id est dubitans, affirmans, negans, pauca intelligens, multa ignorans, volens, nolens, imaginans etiam et sentiens…"}} ("I am a thinking [conscious] thing, that is, a being who doubts, affirms, denies, knows a few objects, and is ignorant of many, [who loves, hates,]{{Efn|the French adds "loves, hates"; hence Veitch's inclusion despite its absence from the Latin here. see Cottingham, J. (ed), 1986, "Meditations on First Philosophy, with selections from Objections and Replies", p.24fn1.}} wills, refuses, who imagines likewise, and perceives").{{efn | This translation by [[John Veitch (poet)|Veitch]]<ref name="Veitch1880">{{cite book | author=Veitch, John | title=The Method, Meditations and Selections from the Principles of René Descartes | publisher=William Blackwood and Sons | year=1880 | location=Edinburgh | edition=7th | pages=115 | url = https://books.google.com/books?id=TjYCAAAAQAAJ&pg=PA115| author-link=John Veitch (poet) }}</ref> is the first English translation from Descartes as "I am a thinking thing".}} This has been referred to as "the expanded ''cogito''."<ref name=Kline1967 />{{efn|[[Martin Schoock]], in the 1642–43 controversy between Descartes and [[Gisbertus Voetius]], fiercely attacked Descartes and his philosophy in an essay.<ref>{{Citation | last = Schoockius | first = Martinus | title = Admiranda Methodus Novae Philosophiae Renati Des Cartes | year = 1643 | url = https://books.google.com/books?id=1PQGAAAAcAAJ}}</ref>
He wrote ''cogito, ergo sum, res cogitans'' and ''cogito, inquiro, dubito ergo sum'' as well as '''''cogito, ergo sum''''' (multiple times) in his 1652 ''De Scepticismo''.<ref>{{Citation | last = Schoockius | first = Martinus | title = De Scepticismo | page = 87 | year = 1652 | url = https://books.google.com/books?id=vW5WAAAAcAAJ&q=%22cogito+ergo+fum%22+cogito+-%22ego+cogito%22&pg=PA100}}</ref>}}