Does philosophy consist of a bunch of more or less unconnected problems or is there a pattern to its problems? Is it possible to order philosophy in a natural and illuminating way, with some areas leading naturally to others, or is it that there is just a loose association of problems that historically we label “philosophy”? Is there a root from which it all springs or is philosophy like a garden made up of different plants (metaphysics, epistemology, logic, ethics, etc.)? I will argue that there is such a root, so that there is a natural order to the various sub-departments of the field. This thesis should shape the way philosophy is taught: it provides a philosophy of philosophical education.
Let me begin with what I shall call the “confident error problem”. This is very familiar to all human beings: not only are we sometimes (often!) wrong about things, we are also very confident that we are right. It isn’t just that we are fallible (it’s a big world and our powers are limited); we are mistaken even when we are totally convinced, supremely confident, and completely certain that we are right. And we are not just wrong but embarrassingly wide of the mark, not even close to being right. This is bad. We are aiming at knowledge, we are sure we have achieved it, and yet we are in complete error. Chagrin is the only reasonable reaction—shame, humiliation. Socrates could make people see this all the time. It is not desirable; it is not admirable. It should be avoided. We therefore need to understand why it happens and take steps to prevent it from happening. But that isn’t easy: the world is full of illusions, people tell lies (or make honest mistakes), we harbor many prejudices, our reasoning ability is limited. Thus, the field now known as epistemology begins—not with a bang but with a whimper (why-oh-why do we fall into such errors?). It seems part of the human condition, but it’s also possible to correct it. We just need to think harder about the problem.
It is easy to see how this problem could lead to inquiries familiar to us from the history of philosophy. First, we need to know what knowledge is; then we will know what it is that is so prone to error. If we have an analysis of knowledge, we will have a breakdown of what needs to be achieved to gain real knowledge. Second, we need to understand perception (including perceptual errors), because this is our primary way of acquiring knowledge of the natural world. Third, we need a good account of reasoning so as to ensure that error does not creep in because of faulty reasoning. This will usher in the study of logic in the broadest sense (induction as well as deduction). We need a general theory of justification. This will include a theory of irrationality—what leads people to irrational beliefs. Inevitably this will lead us to general considerations about the relation between mind and world, since knowledge clearly is some kind of relation between the mind and the world outside the mind. The confident error problem is obviously some kind of mismatch between our mind—our thoughts—and the world we think about—objective reality. If we made no such errors, we would not be compelled to make this distinction; we could lazily acquiesce in a kind of monism of mind and world, since the two never diverge. What we think there is would always be what there is. Epistemology occurs to us because of the possibility (frequency) of error; without error it wouldn’t have the same urgency.
But these epistemological questions quickly raise other questions typically expressed in other words (we shouldn’t assume that philosophy always felt as fragmented as it does today, what with specialization and university curricula). It gives rise to the discipline we now call metaphysics (or ontology). For we now need a description of the world if we are to understand its relation to human knowledge. To what extent is the world dependent on the mind (the issue of realism)? Might it be a projection of the mind (idealism)? Is it such as to be knowable at all? Does perception reveal its full nature? What if it consists of atoms in the void? What if it is ultimately spiritual? For example, we think we have knowledge of causation, but what is causation such that it is knowable by our minds as they are constituted? How do we know about necessity? Well, that depends on what necessity is. What about mathematics, or other minds, or our own mind? We need an account of reality in order to understand how our minds grasp it, or fail to. Thus, epistemology brings metaphysics in its wake; or better, a single field is created that combines inquiries into knowledge and reality. Notice that according to this picture epistemology comes first: it is what gives rise to metaphysics as we historically find it. We don’t just start thinking about metaphysics for no particular reason; we do so because epistemology can’t proceed without it. If we want to know whether perception reveals the objective nature of physical objects, and hence enables knowledge of their properties, we need some idea of what these properties are, and this is the subject matter of metaphysics. The original impetus for metaphysics comes from epistemology, as shaped by the problem of error.
But what about the mind-body problem—how does that fit into this genealogical picture? As follows: once we start thinking about the relation between mind and world, we cannot help wondering how the mind relates to the body. Thinking about perception will lead us to think about the brain as the terminus of sensory stimulation, but then we have to ask how brain events relate to conscious perceptual events. Is the mind really just the brain, so that the mind-world problem becomes the brain-world problem? We are thus plunged into the mind-body problem by reflection on how the mind relates to the world. The philosophy of mind naturally arises from the problems of epistemology; it is one aspect of those problems. It isn’t so much that we have to refute the skeptic, a la Descartes; rather, we have to produce an account of how knowledge works, which requires an account of the mind (and the world). Skepticism is just one response to the problem of confident error; that problem exists whether or not skepticism can be refuted.
How about ethics—how does it arise from the error problem? It arises because ethical error is common and dangerous; it is the domain of confident error par excellence. How can we guard against ethical error? That question can’t be answered without an account of ethical truth—a theory of right and wrong. So, we get subjectivism, emotivism, relativism, and allied doctrines—as well as moral realism, cognitivism, etc. We need a moral psychology, and a moral metaphysics. Ethics is just one more example of how the problem of error can generate the subject we now call “moral philosophy”. Aesthetics is similar: how can we protect aesthetic judgment from the vagaries of human knowledge? For that we need an account of beauty (etc.) and an aesthetic psychology—more metaphysics and philosophy of mind. Ethics and aesthetics are not sealed off from epistemology but link to it in non-trivial ways; the confident error problem is the common thread.
Theory of meaning and philosophy of language generally are natural offshoots of epistemology. Knowledge is a propositional attitude (or some of it is) and hence we need an account of propositions—contents of thought, meanings of sentences. Concepts are elements of propositional attitudes. Evidently propositions do not stand in the way of error; they conduce to it. We do well to understand them if we want to combat error. We may become interested in them in their own right, but they directly link to issues in epistemology; similarly, for spoken words (just think of Frege on sense and reference). The case of action and the will is something of an outlier, but even here we have links to epistemology: for (a) we have knowledge of our actions (a special kind of knowledge apparently), and (b) action results from knowledge (or what passes for it). The error problem is particularly acute in the case of action, because actions performed from error are unlikely to be successful actions. Actions need to be rational and based on knowledge not ignorance. Successful volition needs to be connected to competent cognition. Perhaps this subject (the “philosophy of action”) will come as an afterthought, but it is not completely removed from epistemological concerns. And let’s not forget philosophy of religion: it too is full of epistemological questions. Can we know that God exists and by what means? Is God all-knowing? What is the ethics of religious error? Is faith a way to gain knowledge? Fear of religious error is potent and difficult to prevent—wars have been fought over it! We are an error-prone species and we don’t like it (in ourselves and others); philosophy has its roots in error avoidance, and this concern permeates the field as a whole. It isn’t just a hotch-potch of unrelated problems (a list) but more like a tree structure. A natural way to teach it would be to proceed according the map sketched here, which is discernible in the history of the subject. Philosophy is what you do when faced with the problem of error, especially the persistent confident kind. Is this why philosophers are so obsessed with correcting each other’s errors?
 Socrates’ treatment of Euthyphro is the prime example: the latter is completely confident that he knows what the “holy” is, but Socrates quickly demonstrates that he has no idea. Without such encounters Socrates might have avoided philosophy altogether. Plato, too, was obsessed with the existence of error, as with the cave analogy.
 Knowledge is very important to human beings, but error is its ever-present enemy. Philosophy arises from this tension—between the love of knowledge and its manifest difficulty. I myself have a visceral hatred of error; perhaps that of why I became a philosopher instead of a psychologist.