Cogito, ergo sum 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, ("…—a thinking thing") extends the "cogito" with Descartes's statement in the subsequent Meditation, , or, in English, "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"". Neither nor indicate whether the verb form corresponds to the English simple present or progressive aspect.
Cogito, ergo sum and let him deceive me as much as he can, he will never bring it about that I am nothing, so long as I think that I am something. So, after considering everything very thoroughly, I must finally conclude that the proposition, "I am, I exist," is necessarily true whenever it is put forward by me or conceived in my mind. (AT VII 25; CSM II 16–17) There are three important notes to keep in mind here. First, he claims only the certainty of "his own" existence from the first-person point of view — he has not proved the existence