1.1 What do I know?
Another Ancient Greek philosopher, Plato’s student Aristotle, defined human beings as, “rational animals.” We are like all other animals and come equipped with nervous systems that enable us to perceive what is happening around us and respond in real time. Animal nervous systems are the product of hundreds of millions of years of evolution, and are extremely useful for helping animals survive and flourish in a complex and constantly changing environment. But what is distinctive about the human nervous system is the degree to which the constant stream of information coming into it through our senses is integrated and organized. It is integrated in an experience which is, as far as we can tell, more fully conscious than that of other creatures. And it can be more explicitly examined and critically reflected on, enabling us to reason about how reliable it is and whether what it presents us with is really true. We can make explict to ourselves our own thought processes and subject them to critical analysis.
This is a point that it is hard to overemphasize but also easy to miss since we take it so much for granted. By asking ourselves about the reasons we have for believing that some aspect of our experience is true we are asking ourselves not only about the way things seem to us, but about the way things should appear; not just what we happen to believe about things based on their appearance to us, but about what we should believe about them because it reflects their true reality. And by asking ourselves such questions we are asking what philosophers call normative questions, questions that have to do with values, with concepts like right, wrong, good, bad, true, false, beautiful and ugly. We not only perceive and think, but also judge our own perceptions and thoughts according to standards that are more general and weighty, going by the lofty names of Reason, Truth, Reality and so on.