Charles Peirce’s thought on the relationship between theory and practice has two seemingly inconsistent thrusts. On one hand, Peirce draws theory and practice together. He understands theory as a particular form of practical interaction with the world. On the other hand, he pulls them apart. He seems to insist that theoretical inquiry is not to affect, or be affected by, our other practices. This thesis uses Peirce’s habit-based account of human activity to show that the two sides of his thought are not inconsistent. Rather, Peirce’s apparent division of theory from practice is a consequence of his understanding of theory as a practice.
Peirce often appeals to a habit-based account of human activity. However, this account is not developed in detail in any one text. The first task of this thesis is to gather together Peirce’s remarks on habit and human activity into a single coherent picture. According to this picture, we are made up of a body of habits which is constantly developing as we interact with the world. This body of habits is only partially subject to self-control, but we use this small window to direct ourselves towards our purposes. That in our body of habits which is subject to control is called the ‘foreground’ and that which is not is called the ‘background’. Agents are said to be ‘in harmony’ with their environment when their habits al- low them to achieve their purposes. In the course of articulating this picture points of critical contact with recent philosophy of action are noted.
The second task of this thesis is to show that Peirce understands theoretical inquiry on this model. Theoretical inquiry is the practice directed to the discovery of truth, where truth is understood as ultimate harmony between beliefs (a kind of habit) and the world. It depends on a background of mostly-instinctive habits, including a collection of indubitable common-sense beliefs, and an attunement with the world that enables us to generate explanatory hypotheses.
The third task is to show that Peirce’s division of theory from our other practices is a consequence of his understanding of the special character of truth. According to Peirce the discovery of truth is a ‘long-run’ goal, which demands very different treatment from the ‘short-run’ goals of our other practices. To allow the needs of other practices to interfere in theoretical inquiry would be to take us off the path of truth. On the other hand, to allow theoretical results and reasoning to directly control our other practices would be to substitute reliable instinct for highly fallible reason. In sum, Peirce insists on the autonomy of theory and practice from one another.