The "people are basically stupid" school of philosophy

The most significant thing I learned in my intro Philosophy class was never taught by the professor, but in a heated debate with a fellow-student named Bryan. You see, at the time I was basically a humanist. I believed that all (or at least an overwhelming majority of) people were basically good, and would turn away from their evil ways once someone showed them that they had gone wrong. I also believed (based on God-knows what evidence) that this was a realistic task, though large. I really thought that people in general would be amenable to moral re-education.

Naturally, our class soon enough got to debating the classic dichotomy of whether people are born little angels and then corrupted by the influence of this fallen world, or little devils who need to be whipped into shape before they're fit for human company. Naive creature that I was, I came down mostly on Rousseau's side of the debate, and I was heartily offended when Bryan stated (with great confidence and finality) that the whole debate was missing the point, and that people are basically stupid. So stupid as to be un-trainable, even. (So much for their moral re-education!) Then the class got a whole lot more interesting, largely because Bryan was the only worthy opponent in that class of about 40 students.
(ASIDE: He was majoring in computer science, which implies that he'd been taught enough logic to construct a coherent argument that didn't contradict itself. A rare talent.)

And so: battle was joined. Initially, over Tim Hortons' coffee in the Loyola building, with Bryan hammering on my blind faith in humanity. His weapon of choice was humanity's long and illustrious history of making the same mistakes over and over... For a few examples: war, terrorism, torture, religious persecution, the endless string of corrupt bastards who rise to positions of power, and the number of people who keep getting into the same hopeless relationship again and again with different people. The battle was later continued at his place, over rye and ginger. I fought valiantly, but soon enough it became evident that my opponent was never going to run out of ammunition. He had a better case than I did. Thus, my intellectual integrity forced me to take his position seriously.

I wasn't sold on the idea, but I was forced to start looking at people with this question in mind: Does "basically stupid" describe the observable nature of these creatures better than my existing hypothesis?

Eventually, after adding a few weeks' worth of profoundly unsurprising empirical observations, I was left with no choice but to conclude that yes, the "people are basically stupid" school of philosophy seemed to explain the vast majority of human behaviour far better and more simply than any other approach. Obviously this is a significant generalization. However, both generalizations and assumptions have a useful and necessary place.
DON'T BELIEVE ME? Try to prove something beyond your own existence with absolutely rigorous logic. I'm prepared to accept "I think therefore I am", but anything beyond that involves assuming that your thought-processes (and the input of your so-called senses) bear a direct relationship with some external reality.

It may come as a surprise to many readers that becoming a Christian a couple of years later did nothing to challenge my new (but ever-growing) conviction that Bryan's rather cynical school of philosophy was profoundly accurate. One of Christianity's most central (and most-neglected) axioms is that people, specifically including Christians, are inadequate and flawed. People are not good enough to make it on their own, and have no hope unless it's provided from an outside source. Hence the need for a relationship with God.

Sadly, in all the years between then and now, the evidence has just continued to pile up. I took on the burden of this philosophy against my will, and would be overjoyed at the opportunity to lay it down. However, I cannot do that unless I can exchange it for another theory that explains how people are at least as well.

PLEASE NOTE: All the usual disclaimers apply. This is philosophy: it's taken for granted that not everyone will agree. This writeup relies pretty heavily on my opinion, my beliefs. If you think my opinion stinks, that's okay by me. If you want to convince me that my opinion stinks, then feel free to provide me with a credible alternative. If your argument consists of an all-caps assertion that I'm ugly and my momma dresses me funny, keep it to yourself.