Does the famous Descartes quote "dubito, ergo cogito, ergo sum" suggests secure knowledge of ones existence?

Question

After a discussion about the "difficulties to distinguish knowledge from faith" someone replied to me that the quote implies faith because it uses the word "think". But as it is generally understood:

As Descartes explained, "We cannot doubt of our existence while we doubt." A fuller form, dubito, ergo cogito, ergo sum ("I doubt, therefore I think, therefore I am”), aptly captures Descartes’ intent.

The quote is used by Descartes so to define secure knowledge.

by wiki:

This proposition became a fundamental element of Western philosophy, as it purported to form a secure foundation for knowledge in the face of radical doubt.

This "I am means i securely know that i exist.

https://en.wikipedia.org/wiki/Cogito_ergo_sum

In Principles of Philosophy Descartes's notes:

Latin: "Non posse à nobis dubitari, quin existamus dum dubitamus: at que hoc esse primum quod ordine philosophando cognoscimus."

English: "That we cannot doubt of our existence while we doubt, and that this is the first knowledge we acquire when we philosophize in order."

The proposition is sometimes given as dubito, ergo cogito, ergo sum. This fuller form was penned by the eloquent French literary critic, Antoine Léonard Thomas, in an award-winning 1765 essay in praise of Descartes, where it appeared as "Puisque je doute, je pense; puisque je pense, j'existe." In English, this is "Since I doubt, I think; since I think I exist"; with rearrangement and compaction, "I doubt, therefore I think, therefore I am", or in Latin, "dubito, ergo cogito, ergo sum".

A further expansion, dubito, ergo cogito, ergo sum—res cogitans ("…—a thinking thing") extends the cogito with Descartes's statement in the subsequent Meditation, "I am a thinking (conscious) thing, that is, a being who doubts, affirms, denies, knows a few objects, and is ignorant of many …". This has been referred to as "the expanded cogito".

So the question is what is the consensus about this argument regarding secure knowledge? As i know all major philosophical doctrines espouse it (including idealism of all forms, materialism) and only radical skepticism and poor empiricism tries to attack it.

Answer 1

According to Descartes, his methodological doubt does not confirm his existence as a person with mind and body.

Descartes divides the human being into two components, body (res extensa) and soul = mind (res cogitans). Hence any mental activity, notably doubting or reasoning, demonstrates the existence of mind. But it does not prove that the ideas of his thinking have a relation to reality, i.e. that the ideas refer to existent objects. Hence thinking alone does not prove the existence of the second component, the body.

But Descartes develops an argument how one can conclude that also the body exists. This argument employs the idea of God. It is expanded e.g., in Descartes's Meditation.

For the whole issue see also How does Descartes use god in his Meditations? and Besides the Cartesian Circle, what flaws are there in Descartes' use of God .

Answer 2

See Descartes' Epistemology : 4. Cogito Ergo Sum, for some key points, including :

In short, the success of the cogito does not presuppose Descartes' mind-body dualism.

[...] much of the debate over whether the cogito involves inference, or is instead a simple intuition (roughly, self-evident), is preempted by two observations. [...] As Descartes writes:

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. (Replies 2, AT 7:140).

Answer 3

Your question was, What is the consensus about this argument..?

As Conifold noted, it is not generally accepted today... as an argument. This is not a malign judgment about whether or not things exist. Or even whether "secure" knowledge exists. It is simply that his argument, as observed by Jo Wehler does not really have the sort of empirical component modernity expects and ends up based on intuition, God, and some circularity.

And as Conifold said, it infers an "I" from thinking. Again, this is not a question of solipsism or radical skepticism. It is just that an ""I" has a lot of implications in it. Some might assume it entails a body. Or a certain type of continuity that stands apart from the body. Or a psychological ego with needs of of some sort. So the complaint is that this "secure foundation" is more like a rabbit out of a hat. A more judicious wording might go, "There is doubting, so there is some doubting substance."

In a sense, Descartes was more or less "clearing the decks," and employing radical doubt to refute it. But you are mistaken to assume all the "great thinkers" simply accepted this particular argument. That is not the case for either Kant or Hume, for example, nor for most modern philosophers. What was crucial was Descartes' whole approach.

To say that the "consensus" do not find it inarguably "secure" does not mean a wild leap into nihilism and epistemological anarchy. Indeed, many find Descartes too close to solipsism for comfort. He begins with a cellular autonomy that does not really account for other minds and requires great mental labors and a deity to arrive back at "things."

Answer 4

Is it: Some 'thing' 'thinks' (or produces what we call thought) and therefore some 'thing' is? Wow, that solves everything!

Nietzsche Beyond Good and Evil: Let the people suppose that knowledge means knowing things entirely; the philosopher must say to himself: "When I analyze the process that is expressed in this sentence, 'I think,' I find a whole series of daring assertions that would be difficult, perhaps impossible, to prove—for example, that it is I who think, that there must necessarily be something that thinks, that thinking is an activity and operation on the part of a being who is thought of as a cause, that there is an 'ego,' and, finally, that it is already determined what is to be designated by thinking—that I know what thinking is.

With regard to the superstitions of logicians, I shall never tire of emphasizing a small terse fact, which these superstitious minds hate to concede—namely, that a thought comes when "it" wishes, and not when "I" wish, so that it is a falsification of the facts of the case to say that the subject "I" is the condition of the predicate "think." It thinks: but that this "it" is precisely the famous old "ego" is, to put it mildly, only a supposition, an assertion, and assuredly not an "immediate certainty." After all, one has even gone too far with this "it thinks"—even the "it" contains an interpretation of the process, and does not belong to the process itself. One infers here according to the grammatical habit "thinking is an activity; every activity requires an agent; consequently—."