Descartes, R. (2000). Meditations on First Philosophy. Selections from Meditations 1. In R. Ariew and E. Watkins (Eds.), Readings in Modern Philosophy Volume 1: Descartes, Spinoza and Leibniz, pp. 30-32, 50. Indianapolis, Ind.: Hackett publishing. (Original work published in 1641).
Methodological skepticism = used by Descartes, it adopts (temporary) Skepticism as a methodological stance that can be overcome in order to secure knowledge. For Descartes, skepticism is the first step to reconstruct knowledge on firm foundations
Descartes sees knowledge as the only opinions that can be shown to be “certain and indubitable”, while any belief that can be subjected to even the least doubt will be discarded as though it was false.
Descartes’ strategy is to focus on the general sources by which we acquire beliefs; by casting doubt on the processes by which you acquire beliefs, you can call into question all the beliefs that come to you via those processes.
Skeptical arguments from sensory error
Descartes notes that our senses can be deceptive (optical illusions, mistaking what we see when an object is far away or in the dark, etc.) and that we should not trust any report of the senses as you shouldn’t trust something that has deceived you even once.
Descartes acknowledges that this argument only casts doubt on some sensory information and are usually reliable in everyday conditions, so it isn’t the strongest basis for casting doubt on our perceptual knowledge.
Dream argument
“How often does my evening slumber persuade me of such ordinary things as these: that I am here, clothed in my dressing gown, seated next to the fireplace — when in fact I am lying undressed in bed! But right now my eyes are certainly wide awake when I gaze upon this sheet of paper … I extend this hand consciously and deliberately and I feel it. As if I did not recall having been deceived on other occasions even by similar thoughts in my dreams! As I consider these matters more carefully, I see so plainly that there are no definitive signs by which to distinguish being awake from being asleep.”
Descartes reasons:
- When I dream, I can have experiences that feel entirely real.
- I can’t always tell the difference between dreaming and being awake.
- Therefore, it’s possible that at any given moment — even right now — I might be dreaming. Since dreams can be confused with genuine sensory experience, then all beliefs based on sensory experience are doubtful.
response to the dream argument = even if dream experience are unreliable, that doesn’t mean our waking experiences are unreliable. The dream argument seems too strong; why should we reject all our waking perceptions because we sometimes have deceptive dreams?
The Cartesian problem is that since there are no definitive signs to distinguish waking from dreaming, we can never be certain whether any sensory belief was formed in the reliable waking process or the unreliable dreaming one. Descartes is basing his knowledge on absolute certainty, which comes off as a very high bar. If we accept weaker standards (reasonable certainty), the argument weakens.
knowledge that survives the dream argument = Descartes notes that certain basic things seem to persist even in dreams, specifically a priori knowledge like the science of arithmetic and geometry. So, the dream argument cast doubt on the empirical world but not on purely intellectual or mathematical knowledge.
Evil Genius Argument
Descartes introduces a thought experiment: suppose there is an all-powerful, malicious deceiver who uses all his power to systematically deceive me about everything I believe.
Descartes observes that the Christian God is omnipotent , and so there is a possibility that God deceive us about everything we know.
“Accordingly, I will suppose not a supremely good God, the source of truth, but rather an evil genius, supremely powerful and clever who has directed his entire effort at deceiving me. I will regard the heavens, the air, the earth, colours, shapes, sounds, and all external things as nothing but bedeviling hoaxes of my dreams, with which he lays snares for my credulity.”
His point is that no matter how remote the possibility of the existence of such a being might be, we have to rule out that possibility in order to secure our knowledge on a foundation of certainty. In some sense, we have to be able to prove that we’re not, in all of our thoughts and all of our supposed knowledge, being tricked by an evil agency that’s intent on tricking us.
Outline of Descartes’ solution to skepticism
- The first resolution is Descartes I think, therefore I am (The Cogito) and is the foundation of all knowledge.
- Descartes introduces a rule for certainty: Whatever I perceive clearly and distinctly must be true.
- To remove the possibility of universal deception, Descartes argues that: he has an idea of a perfect, infinite being (God), but that idea can’t come from him since he is imperfect and finite. So, there must be a being as the cause of the idea.
- He reasons a perfect God wouldn’t deceive him as deception is an imperfection.
- All his doubts about the external world are resolved because God created him with a strong natural inclination to believe in an external, material world. Since, God is not a deceiver, that inclination must be reliable