My one quibble with this article, which I think is otherwise spot on in many regards, concerns this claim: "It is more common now to regard humanity as lucid about its interests, and rational in its fulfillment of them (a few behavioral foibles aside)."

There is a strong trend in psychology (both pop and scientific) at the moment to focus on all the ways in which we (or, by an odd synecdoche, "our brains") are irrational (e.g. Dan Ariely).

If you contrast this viewpoint, which I think is increasingly common if not already quite prevalent, with say the viewpoint of intellectuals in the 18th century on "man's nature" I'd say we have a comparatively strong belief in the deep and wide-ranging irrationality of humanity, both when it comes to ends and means.