Hume eviscerates the belief that we can understand anything about the world on a rational and certain basis. At his most optimistic, Hume argues that...moreHume eviscerates the belief that we can understand anything about the world on a rational and certain basis. At his most optimistic, Hume argues that all knowledge beyond direct observation is probable rather than certain. This was an important chastenment of Enlightenment rationalism, and is generally accepted today.
But Hume's argument seems to go much farther, and the more optimistic later sections are the result of his either not recognizing the strength of his earlier arguments or deliberatly obscuring it. In the critical section, "Sceptical Doubts Concerning the Operations of the Understanding," Hume demonstrates there is no rational reason to expect future events to follow the same pattern as those in the past. To have confidence in induction, and thus science and most philosophy, is therefore a matter of faith rather than reason. There is no rational way to understand the world.
In subsequent sections, Hume presents an argument for why we believe in causation and induction. It is because, he says, observing one event invariably follow another creates in our minds the expectation that it will always be so. But, as he demonstrated earlier, there is no rational basis for this belief. Oddly, in the final sections Hume proceeds as if this belief is justified, and offers critiques of miraculous and natural religion.(less)
Kant was a pretty smart guy and maybe I'm not so smart, but I can't understand what he thought he accomplished with the Prolegomena. Kant's stated pur...moreKant was a pretty smart guy and maybe I'm not so smart, but I can't understand what he thought he accomplished with the Prolegomena. Kant's stated purpose was to refute Hume, who had cast doubt on the concept of causation by pointing out that we only observe one event following another and have no reason to conclude that the first caused the second. Kant's solution is posit that all sensory information is subjective. Even so basic information as the spatial and temporal orientation of objects and events is constructed by our minds and bears no necessary relation to reality.
This is a very interesting and influential idea, but as a philosophical solution to Hume's problem, I don't get it. From this starting point, Kant goes on to show that not only causation but other rational constructs are valid. That's nice, but they're only valid in the sphere of ideas. Kant has completely divorced them from any meaningful relationship to empirical reality, because all the information we have about the outside world is a construct of our own minds. Kant allows that there is something out there, but we can't know anything about it as it really is.
Hume, it seems to me, was pointing to a problem with empiricism, which Kant solves by retreating to idealism. That's a kind of solution, but a very unsatisfying one for anyone with any interest in establishing something metaphysical about the world outside one's brain.(less)