Definition of Philosophy

Since you are taking an introductory philosophy course, it is probable that you have not studied philosophy before. Hence, it seems useful to try to get clear from the beginning what philosophy is. On the other hand, if you have studied philosophy before, you probably know that finding out what philosophy is is itself a philosophical task. We will start by trying to give a definition of 'philosophy.' Then you will have a chance to think about what your philosophy of life is.

There are two ways to think about defining 'philosophy': by defining philosophy in general or by defining a "philosophy of S" where 'S' is the name of some system of thought or field of study such as science, physics, history, or mathematics. We will begin by defining "philosophy of S."

A philosophy of S.

Let us begin by looking at examples of a philosophy of S. It is helpful to look at the kinds of questions different "philosophies of S" answer. Suppose 'S' is "science." Philosophy of science answers questions like:

"What is a scientific theory?"

"What types of scientific explanation are there?" and

"What are the differences between laws in physics and laws in psychology?"

Philosophy of religion answers, or at least discusses, questions like

"Does God exist?" and

"How can we know that religious claims are true?"

Philosophy of art examines among other issues the questions:

"What makes something beautiful?" and

"What are the criteria of beauty?"

A philosophy of business might reflect the fundamental operating principles that a person uses in running his business. Examples might be

"The customer comes first." and

"Pay vendors as you would like to be paid by them."

Moral philosophy examines the criteria for right and wrong and good and bad, and seeks to explain the underlying basis for moral judgments.

In these examples a philosophy seems to be an answer to questions about definitions (concepts), or an answer to questions about some kind of conceptual structure created in the practice of a study. Examples of conceptual structures include theories, laws, explanations, and proofs. A philosophy can be appealed to to justify certain choices ("The customer comes first,") or to explain the meaning of certain terms ("A scientific law is such and such.")

There is no way to recognize the statements that are part of a philosophical discussion apart from context. Any statement or sentence whatsoever could be used in a philosophical discussion. For example, someone might give "There is a fly on the wall" as an example of a statement about the external world (the world "outside" our minds) in a discussion about whether we can know anything for certain. And philosophical statements like "God exists" or "Mind and brain are one and the same" can be used in non-philosophical contexts. We should not look for any intrinsic property of statements, then, to distinguish philosophical from non-philosophical ones.

What distinguishes philosophical statements from others is the intent with which they are made, and their context of use. Philosophical statements are often made in a context in which some justification is required for practices within a field of study, when that justification cannot be given by applying the tools of that study itself. For example, the questions of what is a scientific law, or what types of scientific explanations or proofs there are, cannot be answered by the scientific method of hypothesis and proof. It is the very nature of the scientific proofs themselves that are in question. Likewise, the question "What makes something beautiful?," asked as a question about the nature of beauty, cannot be answered by creating more beautiful objects, as an artist does. This question is about what qualities something must have to be counted "beautiful," e.g., harmony, symmetry, etc. Someone who creates beautiful objects must already have some idea of what a beautiful object is.

Philosophical statements are often called "principles." Since we will be using the term 'principle' a lot, let's get clear on its use. The term 'principle' is derived from the Latin word principium, or "beginning," and from the word "princeps," meaning "taking the first part." Other than its association with beginnings, a principle looks a lot like a statement. For example, "Mind is distinct from body" is a principle that looks just like a statement. Let us say that a principle is a statement that is an assumption or is fundamental to a system of thought, leaving these ideas undefined for now.

One way to understand what a philosophy of S is then is to say that it is a justifying principle of S. For example, the political philosophy of communism consists of a principle about how society should be structured. This view is that all goods including property should be held in common and distributed to all as needed. Likewise the philosophy of capitalism consists of the principle that the distribution of goods in society including property should be determined by the free market, i.e., a market operated by private individuals or businesses and free from government control.

How about a philosophy that contains more than one principle? A group of principles forms a set. Is the philosophy identical to the principle or to the view they express? For example, suppose we formulate the philosophy of materialism as:

1. Mind and brain are one and the same.

2. A brain is a purely physical object.

3. All explanations of mental activity can be reduced to statements about brain activity.

These three principles form a set expressing the view of materialism. Since there are three principles and only one philosophy, the most correct view is that the philosophy is identical to the view expressed by the set of principles.

The preceding discussion suggests the following definition of a philosophy of S:

Definition 1. A philosophy is a view expressed by a set of justifying principles of S.

While this definition points us in the right direction, to understand it we must first better understand the relation between philosophy and "S," where "S" is some field of study such as science or art.

One way to understand the difference between science and philosophy is to think about the relation between science and its object of study. Scientists study our experience and the events that occur within our experience and try to formulate laws and explanations which explain and describe these events. Physicists study the rotation of the earth around the sun, the composition of matter, and the relation between matter and energy. But how do they know whether their definitions are consistent or whether their scientific methods are correct? How do they know whether their own assumptions are correct?

It is when scientists or artists have questions about the foundations of their discipline, or the boundaries of their study, or the correctness of their methods, that the need for philosophy arises. Psychologists agree that they study the mind, but what is the mind? How do we distinguish between chemistry and physics? Should sociological laws have the same form as laws of nature? If physics studies matter, how shall we define matter? All these questions involve questions about methods, boundaries, or definitions.

It is at this point that we need philosophy to examine scientific methods, and the conceptual structures created by sciences, including definitions. For example, philosophy of physics examines the definitions used in physics and states criteria for the existence of laws, theories, and explanations. Without a philosophy of physics, physics would be like a house with no foundation: built on an unstable structure and prone to be destroyed whenever any pressure is put on it. A philosophy of physics anchors the science of physics by helping provide correct definitions and by helping the entire structure of laws, theories, explanations, and definitions fit together as part of a single science.

One way to understand the relations between a field of study and its philosophy is by displaying these relations graphically. Figure 1 contains three levels, showing the structure of knowledge.

What is S? 'S' is the name for a field of study such as physics, chemistry, psychology, mathematics, logic, art, etc. If S is a science, S itself will consist of a set of fundamental principles which formulate assumptions, together with laws, theories, and definitions. Philosophy of science studies not just the fundamental assumptions of science but the entire conceptual structure of science: its laws, theories, definitions, explanations, and predictions.

What is 'E'? 'E' is the name for the aspect or element ('E' is for "element") of the world that is the subject of study for "S." For example, the subject of study of biology is living things, so the set of living things is the element of the world studied by biology. Physicists study the physical aspect of the world, while psychologists study minds. Sometimes the "E" element might a set of properties or aspects, rather than just a single one.

What is important to understand in relation to this diagram is that a philosophy of S does not seek to explain and understand our experience of S directly (that's science, art, or some other second-level field of study), but rather seeks to explain and understand the conceptual structures created by the field of study (e.g.,Êphysics, psychology) we use to explain and understand our experience. In order to give a definition of philosophy of S, we must first characterize this second "field of study" level.

What fields of study appear at the second level? Sciences appear there, so we can list psychology, history, chemistry, sociology, physics, neurology, biology, etc. But there are other fields of study that are not sciences of which there might be a philosophy. Examples are art "in general," and particular arts such as music, painting, photography, dance, and fashion design. There are also crafts such as gardening, cooking, and knitting. There are other fields of study which may not fit clearly into any other category, such as religion, mathematics, and logic.

A definition of the second or "field of study" level.

Is it possible to find a general definition which applies to all these second level fields of study? Let us first consider science. The term 'science' is derived from the Latin term sciena meaning "having knowledge". This derived from the Latin term scire meaning "to know." Think of a particular science such as biology. It does seem that the object of biology is to acquire knowledge about living organisms, while the object of psychology is to acquire knowledge about minds. In general, we might say that the object of science is to gain knowledge about the world. Each science selects some aspect or element of the world about which to gain knowledge.

What does scientific knowledge consist of? Scientific knowledge has a linguistic character: it is formulated in the statements of a language. These statements generally take the form of theories, laws, and definitions. Each science is based on one or more assumptions. Because these statements (assumptions, theories, laws, and definitions) are fundamental to the entire structure of a science, they are called "principles." The theories and laws provide knowledge by enabling us to explain, understand, describe, and predict those aspects or elements of the world which the science is concerned to provide knowledge about.

Another characteristic of a science is that it is organized in some way: it is not just a few isolated statements. Yet a science is not identical to the principles which formulate it since these principles can change without creating a new science. Let us create a definition for "the science of S":

the science of S "a field of study whose purpose is to provide knowledge about the 'E' element of the world, i.e., to explain, understand, describe, and predict the 'E' element of the world."

The reason for saying "E element" is that this phrase describes the aspect of the world the particular science is concerned with. For example, physics is concerned with knowledge about the physical world, while psychology is concerned with knowledge about minds.

Consider now a subject of study that is not a science, such as art "in general," or a particular art such as music or painting. Can we identify a single purpose for art or for particular arts? One way to understand art is to say that it's a medium for expression and representation. Music provides a harmonic structure within which it's possible to express feelings and emotions musically, while a painting might represent a feeling or even a perception of an object, scene, or situation. If we accept this idea as a general characterization of the purpose of art, then arts differ according to the medium of expression or representation.

This suggests the following definition for "the art of S":

the art of S a field of study whose purpose is to make it possible to express or represent feelings, emotions, attitudes, and perceptions or to create them in others through the use of some "E" element of the world.

The art of playing piano selects those elements of the world consisting of pianos as a medium of expression and representation, painting selects paint, photography the camera, etc. Some arts are not just subjects of study but are also practiced, but this practice occurs in conformity to the principles of the art (or at least it's intended to!).

Crafts such as cooking and knitting can be given a definition with a similar structure, though the purpose is different: each craft has a particular pragmatic purpose. For example, the purpose of cooking is preparing food to eat.

Is it possible to create a general definition that applies to all these second-level fields of study? In each case we seem to have a set of principles which share a common purpose. This purpose is defined according to some element 'E,' which selects out an aspect or element of the world, and differs according to the field of study.

Let us try to create a definition common to all second-level fields of study:

field of study S a set of statements and practices that share a common purpose which is defined by reference to the "E" element of the world.

Mental exercise.

1. See if you can improve on the definitions of 'science' and 'art'.
2. Try to construct a definition of 'craft' that parallels the definition of 'science' and 'art.'
3. Try to give a definition of 'sport' that parallels the definition of 'science' and 'art.' Can you define a particular sport such as football, tennis, or racquetball?
4. The fundamental assumptions of "second level" fields of study.

Every field of study is based on some assumptions. In terms of the definition of "a field of study" an assumption must be made that there is an "E" element in the world. For example, physics must assume that the world has a physical aspect or element. One physics text begins:

The topic we consider in this book is Physical Science: the body of knowledge that concerns motion; gravitation; electricity; radiation; the structure of liquids, and gases; radioactivity; astronomy; geology; and cosmology. (Physics An Introduction by Pollard and Huston, New York: Oxford University Press, 1969, p. 3)

Here the text attempts to define by enumeration those elements of the world studied by physics. Or, consider these fundamental principles of Euclidean geometry:

1. A straight line can be drawn from any point to any other point.

2. Any straight line can be extended continuously in a straight line.

3. Given any point and any distance, a circle can be drawn with that point as its center and that distance as its radius.

4. All right angles are equal to one another.

Here are some definitions which define some key terms used in these principles:

5. A point is that which has no part.

6. A line is breadthless length.

7. A straight line is a line which lies evenly with the points on itself.

8. A figure is that which is contained by any boundary or boundaries.

9. Parallel straight lines are straight lines which, being in the same plane and being produced indefinitely in both directions, do not meet one another in either direction. (source: Encyclopedia of Philosophy entry under "Geometry")

These nine statements, the fundamental principles together with the five definitions, constitute a partial formulation of the assumptions of Euclidean geometry. A complete formulation would include a complete set of definitions, and might include more fundamental principles.

Here are "the primary assumptions of accounting" according to a recent book:

1. Businesses are ongoing entities with unlimited life.

2. Although businesses have unlimited lifetimes, they require an "accounting" of their actions at least once a year.

3. Some of a businesses's accounts live forever and other parts "die" each time an accounting is made. That is, it will have "permanent" and "cyclical" accounts. (Simplified Accounting for Non-accountants. Hayes and Baker, New York: Berkeley Publishing Group, 1986, p. 209).

Some fundamental assumptions can be stated more simply. For example, here is the fundamental assumption of astrology:

The positions of the planets and stars affect human lives.

The meaning of the phrase "philosophy of S."

All these assumptions are fundamental principles upon which fields of study are based. But these principles cannot be verified by observation. They can only be justified by stepping outside the field of study and into philosophy.

Philosophical Views

What distinguishes a philosophical view from other views, such as scientific views?

A philosophical view is distinguished from other views in several ways:

a) a philosophical view is used to define the conceptual structures or justify the assumptions used in a second-level field of study.

b) a philosophical view in many cases is a view about what ought to be the case as a general principle.

Whether a view is a philosophy does not depend on whether it actually does succeed in defining the conceptual structures or in justifying the assumptions of a field of study, but it must at least be intended for this purpose. Using a), we can define the phrase "a philosophy of S" as follows:

a philosophy of S a view expressed by a set of principles that can be used to define the conceptual structures or justify the assumptions of "S." Here "S" is a field of study that contains a set of statements and practices that share a common purpose which is defined by reference to an "E" element of the world.

Here are some examples of philosophies. Consider the philosophy of empiricism, a view about knowledge. Simply stated, empiricism is the view that all our knowledge is derived from experience. Or, consider dualism as a philosophy of mind. Dualism is the view that mind and body are two separate things. As another example, consider capitalism as a philosophy of government. According to capitalism, government should be organized to allow private property, and free markets should determine the distribution of goods.

Philosophical views in many cases are about how principles should be justified, or about relations among conceptual structures such as definitions, explanations, and theories. Since philosophical views are expressed by statements of justification, they often are view about what ought to be the case as a general principle. For example, according to utilitarianism, a philosophy of ethics, we ought always to do what produces the greatest good for the greatest number of people.

While philosophical views are often simple to state, showing that they are true can be quite difficult and complex. This is true for several reasons. One is that many philosophical views are about fundamental concepts (e.g., truth, knowledge, beauty) that are used in many different subjects of study and in our common-sense beliefs. Another is that because they are both general in scope and fundamental to our system of thought considered as a whole, philosophical ideas have very wide implications. Hence, working out the implications of a philosophical view can be a complex task.

Here are some more definitions of philosophies of different subjects of study:

a philosophy of science a view expressed by a set of principles that can be used to define the conceptual structures or justify the assumptions of a field of study that consists of a set of statements and practices whose common purpose is defined by reference to the scientific element of the world.

a philosophy of psychology a view expressed by a set of principles that can be used to define the conceptual structures or justify the assumptions of a field of study whose purpose is to provide knowledge about the mental aspect of the world i.e., to explain, understand, describe, and predict the mental aspect or element of the world (minds).

a philosophy of art a view expressed by a set of principles can be used to define the conceptual structures or justify a set of assumptions of a field of study whose purpose is to make it possible to express or represent feelings, emotions, attitudes, and perceptions or to create them in others.

a philosophy of music a view expressed by a set of principles that can be used to define the conceptual structures or justify a field of study whose purpose is to make it possible to express or represent feelings, emotions, attitudes, and perceptions or to create them in others through the use of the musical aspect of the world (music).

What is S?

If "S" is the name of a particular science or art, such as psychology, history, or painting, the assumptions or fundamental principles of S stand at the very top of the second (theory) level.

As we have already seen, in some cases, 'S' is not the name of a particular science or art, but instead denotes a general category which contains a number of sciences or arts. "Science" and "art" are examples. The task of these philosophies is to examine the correctness of the principles of all the sciences and the conceptual structures they contain. Philosophy of science "in general" also examines the individual philosophies of particular sciences such as the philosophy of behaviorism and attempts to formulate criteria for the existence of theories, laws, and explanations. Philosophy of science "in general" exists at the third level in the three-tiered graphic. The second or "theory" level can be expanded to allow for different sciences. 

In some cases, the 'S' is not a science or art but a general category of experience such as truth, knowledge, or existence. Do the above definitions work to define a philosophy of S in those cases?

When "S" refers not to a field of study but to a concept such as truth or knowledge, task of philosophy is also to formulate a consistent set of principles in terms of which our beliefs about these concepts can be defined and justified. Though we may not have a science of truth or knowledge, we do have a second level set of common-sense beliefs about truth and knowledge. Hence terms such as 'truth' and 'knowledge' pick out some aspects or elements "E" of the world (truth and knowledge are both aspects of the world). Our philosophy of truth or philosophy of knowledge examines the principles and conceptual structures (including definitions of and statements about knowledge or truth) contained in our common-sense beliefs and tries to define and justify them. This is precisely Descartes' enterprise in the Meditations.

A more intuitive definition

Let us consider the definition of "philosophy of S" again:

a philosophy of S a view expressed by a set of principles that can be used to define the conceptual structures of justify the assumptions of "S." Here "S" is a field of study that consists of a set of statements and practices that share a common purpose which is defined by reference to an "E" element of the world.

This definition includes the definition of "S." Let's simply replace this part of the definition with "S" to give a more intuitive definition:

a philosophy of S a view expressed by a set of principles that is intended to be used to define the conceptual structures and justify the assumptions of S.

This serves as a definition for the philosophy of a particular science. For philosophy of science "in general," we can say:

philosophy of science a view that is intended to be used to define the conceptual structures and justify the assumptions of science.

philosophy of art a view expressed by a set of principles that is intended to be used to define the conceptual structures and justify the assumptions of art.

What is philosophy?

Can we give a definition of philosophy that's not tied to a particular philosophy of S? The definitions already given identify philosophy of S with a view expressed by a set of principles that is intended to define the conceptual structures and justify the assumptions of some subject of study or concept.

The purpose of philosophy as a whole is to create and demonstrate the truth of particular philosophies. A philosophy is a view expressed by a set of justifying and defining principles. Before completing our definition, it's important to add two more components:

1. Consistency. Since philosophy aims at truth, we will write consistency into the definition. If two statements are inconsistent, they cannot both be true. The type of consistency that philosophers are concerned with is logical consistency.

2. Experience. What is the role of experience in philosophy? Experience comes in in the following way. Experience is the starting point for philosophy. The world is divided up according to various "E" elements (e.g., the physical or biological element), based on a similarities in our experience. For example, physical things have certain properties in common (they appear solid, resist touch, stick around when we're not there, etc.). It is these common elements of experience that serve as the basis for categorizing the world into types of elements.

The purpose of the field of study S is to try to understand and acquire knowledge about this element of the world.

Adding consistency and experience to the above definitions, we can generalize the above definitions as follows:

philosophy is an activity whose purpose is to create and demonstrate the truth of views expressed by consistent sets of principles that can be used to define the conceptual structures and justify the assumptions of the fields of study we use to acquire knowledge of our experience.

Challenge: Can you create a more intuitive definition that preserves the meaning of this definition? How about the following definition:

Philosophy is the attempt to impose a consistent set of views on our experience.

Fields of philosophy.

Here are examples of fields or branches of philosophy:

philosophy of math

philosophy of science

philosophy of logic

philosophy of physics

philosophy of biology

philosophy of art

philosophy of business

philosophy of morality = ethics

philosophy of the social sciences

philosophy of truth

philosophy of language

philosophy of psychology

philosophy of life

philosophy of values (value theory)

philosophy of computers

philosophy of mind

philosophy of religion

philosophy of history

philosophy of law

epistemology = theory of knowledge

metaphysics = philosophy of being and existence

Mental exercise

1. Can you think or some other examples of philosophies?

2. Could there be other fields of philosophy that no one has thought of yet?

Applying this definition to "philosophy of life," try to think of what your second level common-sense beliefs are about life. These beliefs include statements about what is important in life, and rules you use to make decisions, for example. Try to think of one or more points of view to justify these beliefs. These taken together are your philosophy of life.

Mental exercise

1. What is your philosophy of life?

2. State, then criticize or defend your philosophy of life.1

1 I am grateful to Victoria Tuck for helpful comments on earlier versions of "What is Philosophy?"

I am also indebted to students in earlier Introduction to Philosophy classes at the University of Massachusetts Lowell for their insightful comments on earlier versions of "What is Philosophy?", and on earlier versions of other materials used in this course.