Max Weber

The German sociologist Max Weber proposed an interpretation of social action that distinguished between four different idealized types of rationality. The first, which he called Zweckrational or purposive/instrumental rationality, is related to the expectations about the behavior of other human beings or objects in the environment. These expectations serve as means for a particular actor to attain ends, ends which Weber noted were “rationally pursued and calculated.” The second type, Weber called Wertrational or value/belief-oriented. Here the action is undertaken for what one might call reasons intrinsic to the actor: some ethical, aesthetic, religious or other motive, independent of whether it will lead to success. The third type was affectual, determined by an actor’s specific affect, feeling, or emotion—to which Weber himself said that this was a kind of rationality that was on the borderline of what he considered “meaningfully oriented.” The fourth was traditional or conventional, determined by ingrained habituation. Weber emphasized that it was very unusual to find only one of these orientations: combinations were the norm. His usage also makes clear that he considered the first two as more significant than the others, and it is arguable that the third and fourth are subtypes of the first two.

The advantage in Weber’s interpretation of rationality is that it avoids a value-laden assessment, say, that certain kinds of beliefs are irrational. Instead, Weber suggests that a ground or motive can be given—for religious or affect reasons, for example—that may meet the criterion of explanation or justification even if it is not an explanation that fits the Zweckrational orientation of means and ends. The opposite is therefore also true: some means-ends explanations will not satisfy those whose grounds for action are Wertrational.

Weber’s constructions of rationality have been critiqued both from a Habermasian (1984) perspective (as devoid of social context and under-theorised in terms of social power)[4] and also from a feminist perspective (Eagleton, 2003) whereby Weber’s rationality constructs are viewed as imbued with masculine values and oriented toward the maintenance of male power.[5] An alternative position on rationality (which includes both bounded rationality,[6] as well as the affective and value-based arguments of Weber) can be found in the critique of Etzioni (1988),[7] who reframes thought on decision-making to argue for a reversal of the position put forward by Weber. Etzioni illustrates how purposive/instrumental reasoning is subordinated by normative considerations (ideas on how people ‘ought’ to behave) and affective considerations (as a support system for the development of human relationships).


In the psychology of reasoning, psychologists and cognitive scientists have defended different positions on human rationality. One prominent view, due to Philip Johnson-Laird and Ruth M. J. Byrne among others is that humans are rational in principle but they err in practice, that is, humans have the competence to be rational but their performance is limited by various factors.[8] However, it has been argued that many standard tests of reasoning, such as those on the conjunction fallacy, on the Wason selection task, or the base rate fallacy suffer from methodological and conceptual problems. This has led to disputes in psychology over whether researchers should (only) use standard rules of logic, probability theory and statistics, or rational choice theory as norms of good reasoning. Opponents of this view, such as Gerd Gigerenzer, favor a conception of bounded rationality, especially for tasks under high uncertainty.[9]

Richard Brandt

Richard Brandt proposed a “reforming definition” of rationality, arguing someone is rational if their notions survive a form of cognitive-psychotherapy.[10]


Abulof argues that rationality has become an “essentially contested concept,” as its “proper use… inevitably involves endless disputes.” He identifies “four fronts” for the disputes about the meaning of rationality:

  1. The purpose, or function, of ascribing rationality: Is it descriptive/explanatory, prescriptive or subjunctive (rationality “as if” real)?
  2. The subject of rationality: What, or who, is rational: the choice, the act, or the choosing actor?
  3. Cognition: What is the quality of the cognitive decision-making process: minimal (calculative intentionality) or optimal (expected-utility)?
  4. Rationale: Is rationality merely instrumental, that is, agnostic about the logic of human action and its motivations (instrumental rationality) or does it substantially inform them (substantive rationality, focusing on material maximization)?[11]

It is believed by some philosophers (notably A. C. Grayling) that a good rationale must be independent of emotions, personal feelings or any kind of instincts. Any process of evaluation or analysis, that may be called rational, is expected to be highly objective, logical and “mechanical”. If these minimum requirements are not satisfied i.e. if a person has been, even slightly, influenced by personal emotions, feelings, instincts, or culturally specific moral codes and norms, then the analysis may be termed irrational, due to the injection of subjective bias.

Modern cognitive science and neuroscience show that studying the role of emotion in mental function (including topics ranging from flashes of scientific insight to making future plans), that no human has ever satisfied this criterion, except perhaps a person with no affective feelings, for example an individual with a massively damaged amygdala or severe psychopathy. Thus, such an idealized form of rationality is best exemplified by computers, and not people. However, scholars may productively appeal to the idealization as a point of reference.[citation needed]

Theoretical and practical

Kant had distinguished theoretical from practical reason. Rationality theorist Jesús Mosterín makes a parallel distinction between theoretical and practical rationality, although, according to him, reason and rationality are not the same: reason would be a psychological faculty, whereas rationality is an optimizing strategy.[12] Humans are not rational by definition, but they can think and behave rationally or not, depending on whether they apply, explicitly or implicitly, the strategy of theoretical and practical rationality to the thoughts they accept and to the actions they perform.