Comment by jancsika
3 years ago
> He means that it implicitly smuggles in a certain conclusion. For instance, "I think therefore I am" seems logically sound, but actually begs the question in presupposing "I" to then conclude that "I" exists.
That's not correct.
It means if something-- anything-- is in the act of reflecting about thinking-- that is, reflecting about thinking about anything at all, including questioning existence-- then that thing exists only in that it is an entity capable of reflecting upon its own existence. And only during the act of reflecting on thinking is this true. And, most importantly, this notion is ineluctably cordoned off from any and all evidence-based logic which requires potentially illusory sensory input.
The part in italics came from others who read and critiqued Descartes. In any case, his basic logic is sound. Hume did the clearest job of critiquing it, and even he didn't claim Descartes had made a logical fallacy here.
It's been awhile since I've read it, but Descartes probably implied his notion was more powerful than it turns out to be-- i.e., that he could build an epistemology on it. Nevertheless, the basic notion is certainly not a logical fallacy.
> It means if something-- anything-- is in the act of reflecting about thinking-- that is, reflecting about thinking about anything at all, including questioning existence-- then that thing exists only in that it is an entity capable of reflecting upon its own existence.
Still presupposing an entity. Why would a thought need an entity at all to think it? Don't you see that this is an implicit assumption that hasn't been justified? Why can't thoughts simply exist without a thinker? A thought can certainly refer to itself, much like a mathematical expression can be recursive.
Here's the fallacy free version: this is a thought, therefore thoughts exist. No entity implied or needed.