What is Philosophy?

The Nature of Philosophy

The word philosophy literally means love of wisdom;1 this tells us something about the nature of philosophy, but not much, because many disciplines seek wisdom. How does philosophy differ from these other disciplines? A brief look at the historical development of the field will help us to answer this question. On the standard way of telling the story, humanity’s first systematic inquiries took place within a mythological or religious framework: wisdom ultimately was to be derived from sacred traditions and from individuals thought to possess privileged access to a supernatural (and, presumably, honest and error-proof) realm; the legitimacy of these traditions or access of these individuals, in turn, generally was not questioned. However, starting in the sixth century BCE, there appeared in ancient Greece a series of thinkers whose inquiries were comparatively secular (see “The Milesians and the Origin of Philosophy“).2 Supposedly, these thinkers conducted their inquiries through reason and observation instead of relying on tradition or revelation. For this reason, they are considered the first philosophers. Although this picture admittedly is simplistic, the basic distinction has stuck: philosophy in its most primeval form is nothing less than secular inquiry itself.3

However, there are now many forms of secular inquiry, so what distinguishes philosophy from them? In the beginning, there was no distinction. But, as civilization advanced, two parts of philosophy became so powerful in their own right that they separated off, claiming for themselves the status of independent disciplines. Mathematics was the first, and split off very early in the game; science (or natural philosophy, as it was called even into the nineteenth century) was the second, splitting off much later. To modern philosophy is left whatever questions these two disciplines cannot solve (at least at a given time), including not only questions that traditionally are thought to be beyond the two (e.g. “What is the meaning of life?”), but also theoretical questions currently at their fringes (e.g. “Can natural selection operate at the species level?”) and conceptual questions at their foundations (e.g. “What is science?”). Philosophy, of course, is best known for the first class of questions, which includes some of the most difficult and important questions there are, such as whether or not there is a god, how one can know anything at all, and how a person ought to live.

Philosophy is characterized as much by its methods as by its subject matter. Although philosophers deal with speculative issues that generally cannot be investigated by experimental test, and philosophy therefore is more fully conceptual than science, philosophy properly done is not mere speculation. Philosophers, just like scientists, formulate hypotheses which ultimately must answer to reason and evidence.4 This is one of the things that differentiates philosophy from poetry and mysticism, despite its not being a science.5

The Branches of Philosophy

The four main branches of philosophy are logic, epistemology, metaphysics, and axiology:

Logic is the attempt to codify the rules of rational thought. Logicians explore the structure of arguments that preserve truth or allow the optimal extraction of knowledge from evidence. Logic is one of the primary tools philosophers use in their inquiries; the precision of logic helps philosophers to cope with the subtlety of philosophical problems and the often misleading nature of conversational language.

Epistemology is the study of knowledge itself. Epistemologists ask, for instance, what criteria must be satisfied for something we believe to count as something we know, and even what it means for a proposition to be true. Two epistemological questions I discuss elsewhere on this site are the question ofhow we can know the future will be like the past, and the question of how we can be sure about anything at all.

Metaphysics is the study of the nature of things. Metaphysicians ask what kinds of things exist, and what they are like. They reason about such things as whether or not people have free will, in what sense abstract objects can be said to exist, how it is that brains are able to generate minds, and whether or not there is a god.

Axiology is an umbrella term for different studies that center upon the nature of different types of value.6 These different studies include aesthetics, which investigates the nature of such things as beauty and art; social philosophy and political philosophy; and, most prominently, ethics, which investigates both the nature of right and wrong and the nature of good and evil. Ethics asks theoretical questions about the foundations of morality, such as whether right and wrong should be understood in a consequentialist or deontological way, but also asks practical questions about the fine details of moral conduct, such as how much moral consideration one ought to give to non-human animals.

Many professional philosophers also double as historians, researching one or another aspect of the history of philosophical thought. Even those who do not conduct novel historical research typically see great value in the texts of thinkers as far back as the ancient Greeks, and study these texts both for philosophical insight and enjoyment. Arguably, history of philosophy may be considered a fifth branch of philosophy.

There also are many “little” branches of philosophy (some of them truthfully quite huge) which address problems and questions that relate to specific other disciplines. There are, for instance, philosophers of religion, philosophers of psychology, philosophers of biology, and (like me) philosophers of physics.

As you can tell, the different branches of philosophy overlap one another. A philosopher considering how much one ought to give to the poor is asking an ethical question. However, his investigations might lead him to wonder whether or not standards of right and wrong are built into the fabric of the universe, which is a metaphysical question. If he claims that people are justified in taking a particular stance on that question, he is making at least a tacit epistemological claim. At every step in his reasoning, he will want to employ logic to minimize the chance of being led into error by the great complexity and obscurity of the questions. He may very well look to some of the ethical, metaphysical, and epistemological writings of past philosophers to see how his brightest predecessors reasoned about the matter.

Aspects of each branch of philosophy can be studied in isolation, but philosophical questions have a way of leading to other philosophical questions to the point that a full investigation of any particular problem is likely eventually to involve almost the whole of the philosophical enterprise.

The Demands of Philosophy

Philosophical inquiry is very demanding, suitable only for those who possess a modest amount of courage, humility, patience and discipline.

Doing philosophy requires courage, because one never knows what one will find at the end of a philosophical investigation. Since philosophy can deal with the most fundamental and important issues of human existence, and since these are things that most people initially take for granted, genuine philosophical inquiry has the potential to unsettle or even to destroy one’s deepest and most cherished beliefs. To engage in genuine philosophical inquiry also is to risk isolation among one’s peers, both for the unorthodox views to which such inquiry may lead, and for the simple unpopularity of critical thinking. A philosopher must be able to face both consequences.

Doing philosophy requires humility, because to do philosophy one must always keep firmly in mind how little one knows and how easy it is to fall into error. The very initiation of philosophical inquiry requires one to admit to oneself that one may not, after all, have all of the answers.

Doing philosophy requires both patience and discipline, because philosophical inquiry requires long hours of hard work. One must be prepared to commit huge amounts of time to laboring over issues both difficult and subtle. People who avoid philosophy often complain that thinking about philosophical questions makes their heads hurt. This is unavoidable: if the answers seem to come easily to you, your inquiries almost certainly are superficial. To do philosophy, one must commit oneself to pain. Those who value truth recognize that there is no shortcut to it: every advance must be fought for tooth and nail.

These virtues always are imperfectly represented in any given person, which is why philosophy is best done in a community: the critical scrutiny of other thinkers provides a necessary check on personal defects invisible to one’s own eyes.

The Rewards of Philosophy

But if philosophy is so demanding, why should anyone even bother with it?

In the first place, there is great utility in philosophical inquiry, even for someone who does not innately care about the pursuit of truth. Consider a random handful of classic philosophical questions: What is the meaning of life? What is the nature of justice? What does it take for a belief to be justified? Is the world we see illusion or reality? The answers to such questions cannot help but to have a critical impact on how one ought to live one’s life. Surely one should subject one’s intuitive beliefs about these things to critical scrutiny, and work hard to come as close to truth as possible. Many philosophical questions are fundamental to human life; the only reason it often does not seem that way is that most people tend simply to assume they know what the answers to these questions are, without ever daring to make a serious inquiry.

This leads us to the second reason why one ought to do philosophy: to understand is ennobling. To go through life simply assuming one understands, is not. To be sure, one can perhaps be happy, at least in the same way as a well-fed dog is happy, if one manages to live one’s entire life without questioning anything. Philosophical inquiry, on the other hand, can be disquieting, offering no guarantee that one’s hard work will yield the conclusions one hopes for. Even worse, philosophy gives no guarantee that one’s investigations will yield any conclusion at all: at the end of the day, one may find oneself not only stripped of the certainties with which one began, but also with no new ones to put in their place. If one does philosophy, one may well have to learn to live with perpetual uncertainty, while others, in their ignorance, happily profess perfect knowledge of things they do not understand at all. But it is clear who has the better life: far better to understand, even if the main thing one understands is the limit of one’s own knowledge.

A final reason for studying philosophy is that, for all of the pains and difficulties associated with it, the pursuit and acquisition of knowledge is enjoyable. To be sure, it is a refined enjoyment, and from the outside it is often hard to see what the appeal is. But once one becomes immersed in it, it carries its own immediate rewards, and even becomes addictive. I have experienced most of the same pleasures everyone else has, but in the end, none of them hold a candle to the pleasures of the mind—to the sheer pleasure of studying and investigating, and sometimes even understanding.


1 From the Greek philia (friendship/love) or philos (friend/lover) and sophia (wisdom). According to the admittedly unreliable Diogenes Laertius (Lives and Opinions of Eminent Philosophers, I.VIII), the term philosopher was introduced by Pythagoras, who preferred it to the less modest title of sophist, or “wise man.”

2 The standard story, wherein the Milesians literally are the first secular thinkers, cannot literally be true; it is scarcely possible that human thought could have been uniformly superstitious—broadly, yes, but not uniformly—at any time in history. However, we have no formal record of the Milesian style of thought prior to the “official” advent of philosophy.

3 To say that philosophy is secular does not mean that it is anti-religious, but only that it is independent of religion. If one needed to be anti-religious or even nonreligious to do philosophy, the history of philosophy would be very slim. To say that philosophy is secular also is not to deny that there are many thinkers, arguably including most of the first philosophers themselves, for whom it is not always clear whether they are doing philosophy or theology: philosophy, like any other discipline, has gray boundaries.

4 In saying this, am I ruling out Continental philosophy by stipulation? I don’t think so, at least not across the board. To be sure, Continental philosophers do not write like analytic philosophers, and I consider that a vice, but I am not sure that their rock-bottom commitments really are that different. The phenomenologists and existentialists I am familiar with seem to base their thought upon rational and evidential grounds as much as anyone else; even with postmodernists, I am not sure that the open disdain for reason and evidence is more than just talk. Am I ruling out from philosophy anyone whose inquiries do not ultimately rely upon reason and evidence? Yes, and unapologetically so.

5 I need to make another qualification here: poetry and literature sometimes can overlap with philosophy. Camus, for instance, expressed himself very well through the medium of novels and plays, but the thoughts he expressed seem to have been worked out by appeals to reason and evidence. I would contrast that with, say, the poem by Whitman that expresses disgust with the way astronomers dissect nature, and contrasts their efforts with the beauty of the night sky. I suspect Whitman was just articulating feelings rather than a position he had worked out rationally: however deep his feelings might be, and however much grist they might provide for a philosophical mill, Whitman still was not doingphilosophy.

6 The term axiology sometimes (and perhaps more properly) is used in a more constrained way, to refer strictly to the study of questions of value; in such usage, axiology cuts across the studies I list, functioning as a component of each rather than an umbrella term for all.

Suggested introductions to philosophy

Lawhead WF. 2015. The Voyage of Discovery: A Historical Introduction to Philosophy: Fourth Edition. Belmont, CA: Wadsworth.

The historical introduction I use in my current Philosophy 101 classes. It is very well-written, and almost entirely secondary text (only a few pages per chapter of original text).

Nagel T. 1987. What Does It All Mean? Oxford: Oxford University Press.

So far, the only topic-oriented general introduction that I really like. It is very short, and does not address some key questions, but it is a great first step.

Stumpf SE, Fieser J. 2007. Socrates to Sartre and Beyond: Eighth Edition. New York: McGraw-Hill.

Another historical introduction I used to use in my Philosophy 101 classes. This one is considerably denser than Lawhead, which may be good or bad depending on your temperament.

Warburton N. 2006. Philosophy: The Classics: Third Edition. New York: Routledge.

Yet another historical introduction I used to use in my Philosophy 101 classes. Each of the chapter covers, in lightning speed, one book by one philosopher. For history of philosophy, this is a great first book. Warburton also offers free audio versions of most of the chapters.