Instrumental Rationality - Definition and Disciplines

Definition and Disciplines

Instrumental rationality is often seen as a specific form of rationality focusing on the most efficient or cost-effective means to achieve a specific end, but not in itself reflecting on the value of that end. Thus, to the extent that rationality is concerned with critically evaluating actions, instrumental rationality tends to focus on the 'hows' of an action, rather than its 'whys'.

More specifically, instrumental rationality can be contrasted with forms of rationality concerned with (a) promoting human understanding on a more general level, or (b) with improving the human condition. Thus, Jürgen Habermas, in his early philosophy of science (such as his book Technik und Wissenschaft als „Ideologie“ from 1968), distinguished between three different forms of "knowledge interests" (Erkenntnisinteressen) that were constitutive of three forms of the scientific enterprise, namely (a) the interest in understanding, constitutive of the humanities; (b) the interest in critical questioning forms of oppression, ideally constitutive of social sciences, and finally, (c) the interest in understanding the necessities of nature and the potential for technically harnessing natural laws, and manipulating living and dead nature, constitutive of the natural sciences. The latter is an expression of instrumental rationality.

However, to a large extent, the social sciences, such as economics, are also investigating how the laws of economy constrain human action and how to manipulate those laws or conditions. Thus, we find in economics many expressions of instrumental rationality. Instrumentally rational agents take the course of action that will optimally achieve their desired ends in any situation, the choice of ends being given. It is distinguished from philosophies that propose to use reason to prescribe the ultimate goals. Instrumental rationality uses reason only as a tool to reach the goals, not to say which goals are right.

Varieties of instrumental rationality include descriptive instrumental rationality (DIR), which says agents behave as instrumental rationalists as a matter of fact; descriptive selfish instrumental rationality, which extends DIR to say that agents pursue selfish ends (e.g., financial gain, pleasure); and prescriptive instrumental rationality, which claims agents ought to pursue their ends as instrumental rationalists.