by Thomas Weston, from the website


What Practice Is

            All labor contains several elements: a goal or goals, a plan of activity for achieving those goals, and actual movements that carry out that plan by changing the form of previously existing material. People often think of labor as a synonym for work, either the kind you get paid for or housework and child care. But the characteristics just mentioned apply to lots of activities beyond work. Playing sports, engaging in politics, balancing your checkbook—all these involve goal-directed physical activity conducted according to a plan. We will use the term practice for labor in this wider sense, and our intention is to use the term to particularly emphasize the activity of labor, as opposed the planning aspect.


Patterns of Practice

            Often the word “practice” is used to refer not to one particular activity, but to a continuing pattern of activity, as when someone says “My practice is to pay the bills on the first of the month.” What is called “practice” in sports or music deliberately builds up patterns of practice so that future labor will be more successful, for example, by playing a game or an instrument well. Political practice fits into this category as well. Making a speech a meeting only one time is less likely to win over your audience than doing it as part of a repeated pattern of practice. Such a pattern of practice will also provide much better information for the person who makes the speech. As a rule, continuing patterns of practice will provide more material for knowledge, as well as developing the capabilities of those who engage in them more than single incidents of practice will.

            Although it sounds odd to say so, practice is not limited to what is practical. People usually call an activity practical if it is part of “making a living,” raising kids, paying the bills. These productive activities are the kinds of practice that most people engage in most often. Artistic or scientific practice don’t need to be practical in these ways, of course, but they still have a connection to practical life.

            In the capitalist system, the practice of production inevitably leads to other kinds of practice, the practice of political conflict and class struggle. Production takes place in the midst of various social conflicts. There are battles over who owns what businesses, over what the pay and hours are, and what tasks that jobs involve. There are also numerous political and legal fights that affect production, for example: Who pays what taxes and how those taxes are used? What public services are there and who gets them? There are social battles concerning who is shot by the cops, or goes to prison, fights in wars, or starves to death. Finally, there are the battles the working class has fought in some countries to overthrow capitalism. All of these conflicts and many others like them are practical, and engaging in them is part of practice.



            Although revolution involves war, most wars are not fought about human liberation, but about which ruling class will get the wealth. Under capitalism, capitalists fight wars for profits and the labor and raw materials (like oil) that capitalists need to make profits and keep their rivals from making them. The practice of these battles between the capitalists of different countries is an extremely important source of knowledge, particularly the knowledge of the technology that is used for weapons. During a war, enormous efforts are make to improve weapons and to modify social organization to contribute to victory. Modern wars have often been a key source for new scientific discoveries and technological improvements in electronics, metallurgy, medicine, nuclear physics, etc.

            The danger and misery of fighting a war, and the atrocities committed by the warring sides make soldiers and their families change their thinking on many topics, adopting new goals and making new demands. The Second World War, for example, changed many peoples’ ideas about the roles and capabilities of women, about racial equality, colonialism, etc. The wars in Vietnam, Iraq and Afghanistan have made people very skeptical about the U. S. government’s aims and its use of war to pursue them. War is a kind of social practice that profoundly affects knowledge. Since it also weakens at least some of the warring sides, however, war also provides one of the most important opportunities for revolution.


Scientific Experiments

            Besides production and social conflicts, there are other important kinds of practice. One kind of practice that is essential for knowledge is scientific experimentation. Experimentation and careful observation provide the evidence for theories in science, whether natural or social. Experimentation is a form of labor in which obtaining information is the main intended result of making planned alterations in some material. Experimentation is often similar to the practice of economic production in the sense that it involves skills and instruments similar to manual labor–experimental scientists often literally “get their hands dirty.” Much experimentation is itself conducted with the intention of applying the results to other practical activities, like economic production or war. In other cases it is part of research conducted for political purposes like sending a mission to the Moon or to Mars to enhance national prestige. Even when such direct connections to production or politics are not present, and whether it is part of research that beneficial or harmful to the working class, experimentation is practice. Other examples of practice that may not be practical (that is, not part of production or social conflict) include playing baseball, drawing a picture, or other artistic activities.


Practice Forms Us

            Not everyone engages in production, but no one can avoid the practical kind of practice altogether. This is obvious for workers, but it is true of the rich, too. Even people who inherit millions have to take action to control how their money is spent and prevent others from taking it from them. Since people are changed by the activities they do, practical activities help make individuals the particular people they are. For most people, the practice of production takes up most of their time and effort, so their concern with this practice is strong, and the effects it has on them are profound.

            People are formed by their practical activities and needs, and anything else they do has to happen on the basis of these activities. But even practice that is not directly involved with production and class struggle can be an important source of information for knowledge.

            We summarize what practice is as follows:


Practice is human activity that deliberately changes the form of some previously existing material. The kinds of practice that are most important for knowledge are production, personal involvement in social struggles, war, and scientific experimentation.


The Test of Practice

            The materialist point of view in the theory of knowledge is that the ultimate test of any view is the effect that the theory has in practice. Marx developed the concept of practice that we outlined earlier and defended the idea that practice is the fundamental source of knowledge and the criterion of truth. Marx wrote that whether something that someone has thought up is objectively true or not is something that can only be decided by referring to practice. That a view is true, and thus has “reality and power,” can only be proved by its success in practice. Arguing over the reality or non-reality of some idea, completely apart from practice, is merely an exercise in hair-splitting.[1]

            These statements do not mean that theoretical controversies are not important. They do mean that controversies can only be settled by connecting the contending views to practice and testing what happens. Frederick Engels wrote that


“Natural science, like philosophy, has hitherto entirely neglected the influence of men's activity on their thought... But it is precisely the alteration of nature by men, not solely nature as such, which is the most essential and immediate basis of human thought.”[2]


            In this passage Engels is talking about knowledge of nature, but the point is a general one. It is human interaction with something through practice, and not simply that thing by itself, which is the most essential and direct basis for knowledge of that thing. Let us call this idea the primacy of practice. The primacy of practice includes the idea that practice with one kind of thing is the most important basis for knowledge of that sort of thing. Understanding of political activism comes primarily from the present and past practice of political struggles. Ideas in physics need to be tested by scientific experiment and observation of physical systems. Different areas of knowledge are not unconnected with each other, but some kinds of practice are more directly relevant than others to a particular statement or theory.

            It is important to realize that the primacy of practice is different from the pragmatic conception of truth. The primacy of practice does not mean that a statement is true because it works for us. It means that the only way that we can tell whether a statement is true is by seeing whether it works. A theory that is never tested in practice could be true, just by dumb luck. We only find out whether it is true by testing it in practice. Practice makes the truth or falsity of a theory known to us, and also changes the world in other ways at the same time. But practice doesn't make truth, since truth is a matter of correspondence with reality.


Practice Versus Passive Observation

            It is important that the knowledge we get through practice is more than we get just by paying attention, or observing carefully. Practice includes changing or trying to change the thing you want to know about, but changing something can reveal its true properties in ways that might never be suspected by a passive observer. Changing something can reveal its hidden weaknesses or unexpected capacities to resist, causal qualities that would not show up in mere observation. Passive observation can only reveal what is superficial, or at least out in the open. It is a fundamental contention of materialism that all things have at least some aspects to their nature that are not superficial, not obvious, an "inner" nature which is more difficult to discover. This does not mean, however, than just any kind of guess about that inner nature reality is part of materialist philosophy. Dialectical materialism rejects the idea that there are gods, ghosts, and magic in the inner nature of things. Theories that say that these things exist are disproved by practice, and believing them makes it much harder for people to understand how they themselves can change society.


January 3, 2012, revised February 8, 2012

“Practice and Knowledge,” by Thomas Weston. From the website This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.

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[1] Theses on Feuerbach, Marx Engels Collected Works, vol. 5, p. 3.

[2] Dialectics of Nature, Marx Engels Collected Works, vol. 25, p. 511.