Bret brings up a good point about being duped by supposedly serious authors even beyond misinformation in the media or on the web. Even after studying something enough to be willing to hold a strong opinion, it is good to allow for being wrong. There are problems of what we don't know but also of thinking things to be true that are not. There are also various forms of knowing as well as limits to any and all form of knowing. This idea is expressed in this Dinesh D'Souza article. Here is an excerpt:
The Fallacy of the Enlightenment is the glib assumption that there is only one limit to what human beings can know, and that limit is reality itself. In this view, widely held by atheists, agnostics and other self-styled rationalists, human beings can continually find out more and more until eventually there is nothing more to discover. The Enlightenment Fallacy holds that human reason and science can, in principle, unmask the whole of reality.
In his "Critique of Pure Reason," Kant showed that this premise is false. In fact, he argued, there is a much greater limit to what human beings can know. The only way that we apprehend reality is through our five senses. But why should we believe, Kant asked, that our five-mode instrument for apprehending reality is sufficient for capturing all of reality? What makes us think that there is no reality that goes beyond, one that simply cannot be apprehended by our five senses?
Kant persuasively noted that there is no reason whatsoever for us to believe that we can know everything that exists. Indeed what we do know, Kant said, we know only through the refracted filter of our experience. Kant argued that we cannot even be sure that our experience of a thing is the same as the thing-in-itself. After all, we see in pretty much the same way that a camera does, and yet who would argue that a picture of a boat is the same thing as a boat?
Kant isn't arguing against the validity of perception or science or reason. He is simply showing their significant limits. These limits cannot be erased by the passage of time or by further investigation and experimentation. Rather, the limits on reason are intrinsic to the kind of beings that humans are, and to the kind of apparatus that we possess for perceiving reality. The implication of Kant's argument is that reality as a whole is, in principle, inaccessible to human beings. Put another way, there is a great deal that human beings simply will never know.