The Status of Reality

4It is without doubt Friedman’s (1953) work that gives us the truly contemporary formulation of the problem of the relation between theory and reality in economics. [6] For, breaking with the classical realism of the nineteenth-century economists, [7] Friedman seeks to show that a hypothesis does not have to be immediately realist—that is to say, it does not have to refer to a directly observable situation. He illustrates this assertion with the example of the law of falling bodies falling in a vacuum. This law is fruitful because “under a wide range of circumstances, bodies that fall in the actual atmosphere behave as if they were falling in a vacuum” (1953, 13). [8] Nevertheless, this does not at all mean that in fact “the formula assumes a vacuum” (1953, 13). In the same way, Friedman tells us, the economic hypothesis according to which it is “as if [companies] pushed each line of action to the point at which the relevant marginal cost and marginal revenue were equal” (1953, 16) is not to be judged on the basis of the way in which businessmen really and concretely make their decisions, in so far as “of course, businessmen do not actually and literally solve the system of simultaneous equations in terms of which the mathematical economist finds it convenient to express this hypothesis” (1953, 16). What is important is that everything happens as if people calculate in this way, just as everything happens as if the body were falling in a vacuum. Consequently, a hypothesis does not have to be directly realist, and its validity will be demonstrated if the predictions realized on its basis are most often corroborated by experience: “The hypothesis is rejected if its predictions are contradicted (‘frequently’ or more often than predictions from an alternative hypothesis); it is accepted if its predictions are not contradicted; great confidence is attached to it if it has survived many opportunities for contradiction” (Friedman 1953, 7).

5As we see, the irrealism of hypotheses is advocated here in order to align the approach of economics with the approach of physics, not so as to adopt a more regulative, or even relativist or skeptical, position. [9] In fact, Friedman’s recourse to the “as if” aims to permit a greater modelization, and thus mathematicization, of the discipline. The irrealism of hypotheses is a part of Friedman’s ambition to make economics a science on the model of physics and to constitute the discipline on the basis of the criteria of logical positivism: mathematicization and prediction. But whereas an ever-greater modelization of the economy, initially, had as its corollary the idea that these models may predict real phenomena, [10] it turned out that, in the last instance, the relation to the real was no longer defended except in hypothetical form. As Mäki emphasizes, we have arrived at a paradoxical situation where to do science means to postulate that “Entity X might exist, Theory T might be true” (Mäki 2002, 92) without ever being able to prove it. From the proposition “it is as if agents maximized their profit,” we have arrived, over time, at “it is as if this proposition were scientific.” This failing of “blackboard economics” [11] obviously generated various responses which are not satisfied with the simple affirmation according to which scientific theories X “might relate to entities that themselves might exist,” but which do indeed try to show that “scientific theories are, and must be, constructed and employed with the aim of describing the causal processes that constitute the way in which the world works” (Mäki 2001, 371). Our aim here is neither to critique mathematical models nor to give an inventory of the multiplicity of approaches in economics, which have a widening distance from “the way the world works,” but to make visible the skeptical or relativist trend of a theory (Friedman’s) which at the start, obviously, was not skeptical or relativist at all, since it inscribed itself explicitly in the wake of logical positivism. For, if to think economics as a science means merely to postulate that theory T “might” be true and that what it speaks of “might exist,” then it is clear that an initial positivism has undergone a metamorphosis, to the point of agreeing with certain forms of relativism and skepticism. This becoming-skeptical of economic science is sometimes clearly propounded by certain epistemologists of economics. Thus, McCloskey (1994) thinks that economics involves an analysis in terms of rhetoric, whereas Weintraub (2002) shows the extent to which economists’ language is linked more to the evolution of mathematical language than to the consideration of reality. Ochangco (1999), in an interpretation that uses the notion of language games in a skeptical framework, shows, on the basis of an analysis of the notion of value, that different definitions exist but that they cannot be evaluated against each other because they belong to incommensurable language games. [12]

6Now, what matters to us here is that the becoming-skeptical of what amounts to the great majority of works in economics today, is parallel to the becoming-skeptical of philosophies of science which take as their starting point a reflection on physics in its relation to experience. To develop this point, let us recall that Popper, against the realism of the Vienna Circle, which he judged to be too immediate, established that a scientific theory cannot be validated, but only falsified, by experience. Although falsificationism renounces “any claim implying that theories can be established as true” (Chalmers 1976, 34), science is nevertheless distinguished from pure ideology in so far as it, and it alone, can be submitted to empirical testing and can develop protocols for evaluations against the real. This exigency, which is no longer a positive affirmation of the veracity of physical reference (logical positivism) but a submission to the possibly negative verdict of experience, will be judged by Lakatos as still being too dogmatic. For him, Popperian falsification presupposes the distinction between theoretical or speculative propositions and factual propositions immediately referable to experience (Lakatos 1970, 7s). Now, the reality of this distinction—a necessary condition in order for scientific theory to be falsifiable—in fact turns out to be impossible to establish. Consequently, scientific discourse is no longer possible—that is to say, a discourse of propositions that can be qualified as scientific as opposed to ideological propositions.

7

If . . . accepting the demarcation criteria of dogmatic falsificationism, we deny that facts can prove propositions, then we certainly end up in complete skepticism: then all science is undoubtedly irrational metaphysics, and should be rejected. Scientific theories are not only equally unprovable, and equally improbable, but they are also equally disprovable” (Lakatos 1970, 19).

8To escape this impasse, Lakatos develops his methodological falsificationism, [13] for which a hypothesis’s pertinence (it is no longer a question of the reality of the reference intended by the statement, but of a degree of acceptability of such a proposition by the community) will depend upon its capacity to resist history for as long as possible. It is therefore, in the last instance, history that will tell whether a research program will “degenerate” or not. [14] This weakening of Popper’s falsificationism logically leads to the relativism frankly advocated by Feyerabend. If, Feyerabend explains, only history (that is to say, the necessary utility or needs of a civilization at a given moment) allows us to attribute a scientific status to a discipline at such a moment, then current science has no more scientific legitimacy than ancient myth. Further still, Lakatos, says Feyerabend, “arbitrarily selects science as a measure of method and knowledge without having examined the merits of other professional ideologies” (Feyerabend 1975, 237). In short, we must be willing to adapt to a world where there is as much “truth” in the novel as there is in scientific discourse, where the statement “the earth is blue like an orange” is just as valid as “the earth rotates.” Feyerabend presents this frankly relativist thesis as the consequence of Lakatos’s thesis, itself a consequence of the “dogmatism,” judged to be still too close to logical positivism, of Popper—who himself aimed to relax the logical-positivist hypotheses he thought too “dogmatic.” What can we conclude from this analysis of the development of each of the positions involved? Firstly, that the “dominant” economics, just like philosophy of science in its Popperian aspect, is directly under threat from skepticism and radical relativism. Echoing the absolute relativism of Feyerabend, certain historians of economic thought conclude as a consequence that their interrogation must bear not upon the truth value of economic propositions but upon the rhetoric employed by economists. This is, for example, the project of McCloskey, who writes: “We need a new philosophy, or anti-philosophy, to understand economic science as it actually works. The form of anti-philosophy recommended here is the oldest one: ‘rhetoric’” (1994, xiii). This skepticism, far from being the opposite of positivism, seems to be an expression of its natural evolution. The oscillation between positivism and skepticism is not a pendular movement carrying us from one position to its opposite, but seems instead to belong to a logical tendency, since positivism generates relativism internally. This becoming-skeptical of positivism seems to be the principal pitfall toward which current economic theories are converging. Therefore, is this nullifying aporia (in which one position seems to imply its opposite, logical positivism calling for Feyerabend) inherent to the question of reality, or does it also afflict debates concerning the rationality of agents?

The Rationality of Agents

9Obviously economics contains multiple ways in which to think the rationality of the agent. Nevertheless, this multiplicity, far from being irreducible (with as many definitions of rationality as there are economists) can be boiled down to three broad groups.

10The first way, that of neoclassical economics, consists in positing the hypothesis of unlimited rationality. Within the framework of this hypothesis, which gave rise to Homo economicus, the perfectly rational agent adopts the behavior that leads to general equilibrium (this behavior being the best possible response, once the scarcity of resources is taken into account). The infinite multiplicity of behaviors observed in reality is reduced to one single model of the so-called “representative agent.” This representative agent, supposed to incarnate all individual agents, [15] knows, by definition, how to maximize his interests. [16] This hypothesis implies that the agent has at his disposal an infinite capacity for calculation and perfect information about the world, allowing him to make the best possible choice. This unlimited rationality is similar to the rationality of the Leibnizian god, who is omniscient, and calculates the best of all possible worlds. In this hypothesis, the agent’s behavior is entirely determined by the calculations he carries out—just as, in Leibniz, God’s will is subservient to his understanding.

11This conception, still dominant in economics, of a human rationality equivalent to that of a Leibnizian God, obviously finds itself opposed by the hypothesis of limited rationality. Within this second broad category we might recognize two subgroups. In other words, we find, in economics, two main ways of moderating the hypothesis of the perfect rationality of agents: either by saying that agents do not have perfect information about the world at their disposal, or by saying that they do not have an infinite capacity for calculation.

12The first way (imperfect information) leads to a sophistication of the analysis of the behavior of agents, who must, in order to make decisions: (A) anticipate other agents’ possible actions; and (B), construct contractual arrangements to reveal information and to avoid behaviors that seek to profit from asymmetries in information. But being able to anticipate in a world where information is imperfect becomes an extremely complex matter. In such situations, if agents wish to coordinate effectively, they will have to put in place devices through which information can be acquired or revealed. [17] To the calculations of the maximization of interest, the agent will therefore have to add calculations of the costs of finding information and/or calculations of the costs of the devices necessary for the revelation of information. [18] To resolve these complex problems, individuals would have to possess a calculatory capacity as great as that necessary for the agent in the situation of unlimited rationality. The second way of relaxing the hypothesis of unlimited rationality consists in considering that even in a situation where agents have at their disposal all information necessary to take an “optimal” decision, nothing assures us that they will actually do so (Heiner 1983). We are thus confronted here with an effective limitation of the cognitive capacity of agents (imperfect information, limited capacity for calculation). The rules of the functioning of the economy (the institutions, to use North’s expression) serve to palliate this cognitive limitation of agents, and to facilitate their choice, inducing certain regularities in their behavior. [19] Thus reformulated, the question of rationality becomes a more directly general question, close to philosophical, anthropological, or sociological thematics. (Is reason an adequate response to a set of external stimuli? [20] A simple calculation on the basis of individual interest? Free reflection? The product of genetics? Adaptation to the environment? And so forth.) In this framework, the problem for the economist becomes that of knowing how to characterize the type of regularities that he is trying to uncover in the behavior studied. Is it a question of an entirely predictable regularity, in which case a certain type of determinism or necessitarianism of behavior can be posited; or does the agent’s behavior remain so unforeseeable and irreducible to any regularity that ultimately any hypothesis about this behavior will be in vain? It is between these two extreme limits that we find set out the different studies that accept the general hypothesis of this type of limited rationality. [21]

13For example, Hodgson (2001, 2004), taking up the thesis of so-called universal Darwinism, posits that the concepts of Darwinism—heredity, variety, and selection—can be applied to all complex systems. [22] Each of these concepts in fact has an equivalent in economics: “Underneath the very real differences of character and mechanism, biological evolution and economic evolution might have types of process or structure in common, when considered at a sufficiently general level of abstraction. At this level, we are not addressing mere analogy. We are considering a degree of identity in reality” (Hodgson 2003b, 368). At this level, the habits of individuals may, on the model of genes in biology, be considered as possessing inherited characteristics (storage and transmission) in so far as they say in what manner it is possible to act (storage) and are transmissible by imitation. [23] So there exists a social equivalent to the biological gene, in the form of habits, encompassing habits of behavior and of thought alike. In sum, “the crucial point is that all action and deliberation depend on prior habits that we acquire during our individual development” (Hodgson, 2003a, 167). Habits are, therefore, essentially the result of social causes explained in biological terms. Thus, we have here an attempt at the reduction of the behavior of agents to regularities governed by necessity. As is the case for every naturalism, [24] of which Hodgson’s evolutionism is a foremost case, it is a matter of thinking rationality on the basis of laws of nature. [25]

14In opposition to such an enterprise, other economists recuse any application of determinism to human behavior, any submission of rationality to natural laws; thus Commons, for example, takes into account the factor of human will, and shows how the human sciences, unlike solely natural sciences, must accept what he calls “voluntarity”—that is to say, “the active and organizing character of thought” (Bazzoli 1999, 72). [26] “To suppose that the product of human action is predictable, is to inscribe it in a determinist conception of the world (the world follows a rational order) and to deny the complexity and incompleteness of evolutionary systems” (Bazzoli 1999, 76). But how far can we push this incompleteness without renouncing the discourse of science, which serves to establish regularities? Commons advocates Peirce’s pragmatism, but how far are we to go in the interpretation of this “pragmatism?” Must we, like Rorty (who sees himself as its most complete representative) go to the extent of “considering science as a genre of literature” (1982, 63)? Is not complete relativism the vanishing point of pragmatism? [27]

15However this may be, two extremes limit economists’ inquiries on the question of the rationality of agents: on one side, an explanation of the behavior of agents on the basis of laws, an explanation that always induces a certain form of determinism (the Leibnizian God or the submission to historico-biologico-social laws); on the other, the threat of relativism as incarnated by Rorty, when he thinks of scientific theories as many different forms of rhetoric. Most authors situate themselves between these two extremes, oscillating between the two positions, sometimes juxtaposing them. [28]

16Thus, at the end of this analysis, we can allow ourselves to characterize the principal aporias that the epistemology of economics encounters relative to the two questions that structure it (those of reality and rationality). In the first case, we have shown the paradoxical engendering of skepticism on the basis of positivism; in the second, the constant oscillation between these two extremes. Certainly, in both cases, most authors seek to occupy median positions—for example a Popperian position in the debate on the status of reality, or a Peircian position in the controversy over the nature of rationality. However, is not such a position condemned to the problematic juxtaposition that leads finally to relativism, the true vanishing point toward which they all converge, and on the basis of which they are all ultimately organized? In other words, do we not find the truth of Popper, in fact, in Feyerabend’s position, that of pragmatism in Rorty’s—just as, moreover, the latter both affirm? Faced with this situation, must we not find another angle from which we can pose these questions in another way? Is it possible to organize the space of discussion of economics otherwise than on the basis of this one sole vanishing point?

Definition of the Transcendental Argument

17The angle from which we propose reconsidering the preceding questions is a type of argument that, since Strawson, has been called the transcendental argument, and which, as S. Laugier reminds us, stimulated debates “that dominated analytic philosophy at the end of the twentieth century” (2000). Let us recall, then, that Strawson (1966, 72–89) identifies in Kant a type of argument that seeks to show that if one does not accept a certain concept, then one can neither think nor act as one in fact does. [29] Thus, Kant justifies the recourse to a concept of cause by indicating that this concept is the necessary condition of our experience of succession. Showing how certain concepts or series of concepts are necessarily implicated in cognitive operations which, in fact, we do carry out is, to Strawson’s eyes, the core structure of the “transcendental argument.” He will utilize this argumentative device to show, for example, that we could not differentiate the objects we perceive were we not able to think ourselves and the objects as two entities coexisting in space. Following him, G. Evans (1982), setting out from a general type of cognitive operation presently effectuated (such as, for example, perceiving objects, referring to something, or predication), tries to identify the presuppositions it necessarily implies. In the same way, J. Habermas and K. O. Apel use this type of reasoning when they undertake to bring to light the necessarily underlying conditions of our common communicational experience. The transcendental argument thus consists in drawing out the presuppositions that are necessary to an experience of thought or speech that, in fact, is familiar to us. It does not bear directly on the reality of the world, but on cognitive operations. [30] With it, it is possible to show that the everyday representations of human beings would not be possible without a certain number of conditions, conditions which it is the researcher’s aim to determine. This is why the transcendental argument is often stated in a negative manner through propositions of the type: “We cannot do otherwise than to posit q,” or “We cannot not posit such-and-such conditions, in order for such-and-such representations or operations to become intelligible.” It is clear, within such a framework, that the more difficult it is to question the initial premise or factum, the more compelling the transcendental argument will be.

18Given this general definition of transcendental argument, we must consider the first attempt to introduce it into economics—that of Lawson.

An Attempt to Introduce the Notion of Transcendental Argument into Economics: The Example of Lawson

19To our knowledge, Lawson is the first to utilize, expressis verbis, the notion of transcendental argument in the field of economics. His objective is to respond to the twofold question of the relation between economic discourse and reality on one hand, and that of the nature of the rationality of agents on the other, with, in both cases, the intention of overcoming the arguments of skeptics and radical relativists. [31]

20As far as the first question is concerned, the inability of today’s scientific activity to demarcate itself from other activities (such as that of fiction), according to Lawson, is the result of the runaway success of Popperian falsifiability. Resorting to the transcendental argument, for Lawson, consists in demonstrating the impossibility of not positing reality. In his argument we find a negative form—“one cannot not posit X”—whose inherence to the transcendental argument we have already noted. In this regard, Lawson writes: “Thus, those who would reduce science to a conversation presuppose objects of that conversation. Even if they claim that conversation is only about conversation they thereby introduce a distinction between the conversation as an (intransitive) object of knowledge, and conversation as a (transitive) form or medium of knowledge” (Lawson 1997, 48–49). Thus the “conversation” of economists bears upon an object—“economic reality”—and they cannot not posit this reality as their horizon.

21This realism—which overcomes the skeptical objection and which is doubtless more secure than that with which Bouveresse (1992), for example, will counter Rorty, under the name of a “motivational realism of science”—nevertheless does not yield a discriminating criteria able to tell us why the theory of general equilibrium, or universal Darwinism, might be better than other concurrent theories. Realism as advocated by Lawson is not incompatible with the affirmation of an infinite pursuit of the determination of reality: “I have allowed that things exist and act independently of their descriptions, this stance is complemented not by an absolutist or foundationalist position in knowledge but by an epistemological relativism, by the thesis that we can only know these things under particular (historically and socially relative) and potentially transformable descriptions” (Lawson 1997, 58). [32] In this precise case, the transcendental argument consists in showing that we cannot not affirm a certain form of reality. Thus, it allows us to avoid the slippery slope of fallibilism; but it does not at all seek to determine directly which theory best reveals this reality (that is to say, for Lawson: its structures, mechanisms, powers, tendencies).

22The author uses the same argument to confront the question of the determinism of the behavior of agents. For example, he undertakes to show how a certain freedom of agents is a necessary condition that cannot not be posited. If one “holds that, under certain conditions x, an agent chooses in fact to do y,” this means that one maintains that it “could really have not chosen y” (Lawson 1994, 269). Without such an argument, according to Lawson, the notion of choice obviously becomes meaningless. Here again, the type of argumentative strategy proper to the transcendental argument appears clearly: we begin here with a fact, which is a cognitive operation rather than a substantial entity, namely that we speak of a choice between x and y. Now, to speak of “choice” presupposes a certain number of conditions without which this usage would be meaningless. Among these implicitly presupposed conditions is the capacity of agents to not have an entirely predictable behavior reducible to an external causality.

23Nonetheless, as Viskovatoff (2002, 703) notes, such a transcendental argument rests upon a postulated premise—namely, “the intuition that human agents have the ability to make real choices” (Lawson 1994, 269). Consequently, if the transcendental argument has a certain validity, this validity is linked to the truth of the premise thus posited. This is admitted by Lawson, who writes: “It is necessary to recognize that the premises of the transcendental argument are always contestable, never indubitable” (1994, 271).

24Doubtless it is on this point that it seems possible to go further than Lawson, who, to our eyes, does not deploy the full potential of the transcendental argument. For Lawson considerably weakens the argument by reducing it to a chain of reasoning of the type: p; p would not be possible if we did not think q; we must think q; it is true or necessary that q. [33]

25Such a chain of reasoning is in fact entirely reducible to a classical logical argument (for example, one of the modus ponens type). For proposition two (“p would not be possible if we did not think q”) can be unpacked as follows: that proposition one (p) presupposes proposition two (p would not be possible if we did not think q) means that one is only true if two is true. The transcendental argument would thus be nothing but a deductive logical argument in which proposition two is just a premise with the status of a postulate. This is why A. Boyer (2002), challenging the specificity of the transcendental argument, will affirm that there is no place in science for arguments other than:

26(a) Deductive arguments, in which the conclusions cannot contain anything more than the premises, and in which, consequently, all ampliative inference is necessarily illegitimate. These deductive arguments cannot be said to be absolutely certain in so far as the premises can never be anything other than postulates admitted by pure convention (such as, for example, Euclid’s parallel postulate).

27(b) Inductive, generalizing inferences, which, certainly, help orient us in the real, but never have any definitive validity whatsoever, since they depend on experience.

28This is why, Boyer concludes (2000, 37), recourse to the transcendental argument is in vain in so far as “reasoning is either deductive or non-deductive: in which case, it is inductive. Tertium non datur.” Faced with this objection, to which Lawson’s utilization of the transcendental argument is assuredly vulnerable, we should like to propose a version of the transcendental argument that prevents it from removing its specificity.

Another Version of the Transcendental Argument: Performative Noncontradiction as Structure of Transcendental Argumentation

29The contribution of K. O. Apel, in relation to the accepted meaning (as Strawsonian as it is Habermasian) of the notion of the necessary condition of possibility of a fact, is to have thought this notion on the basis of the concept of performative noncontradiction. He writes, on this subject: “I am of the view that it is important to reflect, at the beginning of any philosophical work, and thus equally at the very beginning of our analysis of the lived world, about necessary transcendental presuppositions of argumentative discourse—that is to say, about what cannot be contested without performative contradiction” (1981, 924). In Apel, the transcendental presupposition becomes synonymous with pragmatic or performative noncontradiction. Let us recall briefly that performative contradictions are by definition always false, not because of their meaning, as in the analytic proposition: “every married man is a bachelor,” but because of the status of their utterance. [34] Because of this, since the contrary of always-false utterances is necessary, then we can term “pragmatically necessary” utterances that cannot be denied without self-contradiction. It is clear here that performative contradiction is not reducible to strictly analytic (A is A) or deductive (if A then B) formal reasoning, but is defined strictly as a statement that annuls itself from the very fact of its having been said. Within this category, two types of contradictions can be discerned: (1) “pragmatico-empirical” contradiction, which is to do with the empirical conditions of discourse. In this case, the content of discourse and the empirical conditions that must be in place in order for this discourse to take place are performatively contradictory, as, for example, in the statement: “Here I am in this shipwreck, of which there were no survivors;” (2) “pragmatic-transcendental” contradiction, which has to do with the conditions of fact of the argument itself, for example when I say: “Truth does not exist.” We find this second case in the classic self-refutation of radical skepticism, and the consequent necessary suicide of the sophist. As the inverse of this self-contradiction, performative noncontradiction postulates the necessary congruence between the statement and its utterance. So how does this reformulation of the transcendental presupposition in terms of performative noncontradiction allow us another employment of the argument in the specific field of economics?

30We can show this first of all on the basis of Lawson’s first question as to the status of reality. In fact we can show not only that a minimum of realism must be posited, but what is more, that it is contradictory not to hold that, in this matter, one hypothesis is better than the others. To do so, let us take Feyerabend’s example, which posits that “the only principle that does not inhibit progress is: anything goes” (1975, 20). In saying this, he falls into the following aporia: If “anything goes,” then this means that the proposition “anything goes” cannot be accepted. Here we can see the contradiction between the content of the proposition (“anything goes”) and one of its presuppositions (that the proposition “anything goes” must be accepted). This type of contradiction allows us to assert that the thesis according to which all hypotheses are valid cannot be accepted, since, at a certain level—that of the justification of this hypothesis itself—it contradicts itself. The proposition “there is a hypothesis that is better than the others” must therefore be accepted, since its contrary is always false. This obviously does not determine the content of the hypothesis likely to speak more correctly of this or that reality; but it does lead, against relativism, to a position that goes beyond Lawson’s, in so far as it lets us say that some hypotheses are indeed better than others, and that science cannot not presuppose this point. It is possible, then, to see here a difference with the “motivational realism” formulated by Bouveresse, according to which scientists have a propensity to presuppose a reality, and if they did not do so they would have to stop working. The transcendental argument is more constraining, since it says that it is inherent to scientific discourse to make this presupposition because, were it to posit the inverse, it would negate itself, self-destruct, contradict itself. Generally speaking, it is a question of accepting a detour via metatheory, qua interrogation of the “claims” of a discourse, in order to be able to determine to what extent certain stances are inconsistent. Feyerabend, asserting that “anything goes,” claims the validity of his discourse, and cannot not make this claim in relation to the regime of discourse he is invested in (a nonliterary regime with a claim to validity). With regard to this claim inscribed within his sentence, the latter becomes necessarily false—falsified not through recourse to the empirical but through the consideration of its pragmatic consistency (performative contradiction).

31This transcendental argument reformulated on the basis of performative contradiction allows us, furthermore, to sketch out responses to the second question that economics poses, in relation to the rationality of agents. For with the aid of this argument, we can show how certain theories about “human rationality” self-destruct. For example, to reduce human rationality to a pure calculation of strictly individual interest (something frequently considered in economics) comes down to claiming, at the same time, that the scientific discourse that affirms this proposition is itself also the product of pure individual interest; in which case, it has no general validity, and there is no need for us to discuss it or to argue against someone who implicitly tells us that, in saying what he says, he does nothing but express the preferences of an individual interest.

32The necessary compatibility between the rationality imputed to agents and the rationality exercised by the economist implies the impossibility of certain hypotheses. [35] The metatheoretical aspect thus turns out to be decisive, including at the level of the most specific theses. Now, it has to be said that few economists take it into consideration, and this disinterest cannot boast that it is anchored in the concrete, since we have seen the extent to which taking this abstract level into consideration allows the evacuation of a number of self-contradictory theories. Simon was not wrong in wanting to consider this aspect of the question as inherent to any reflection on economics. It is through a confrontation with his theory that we wish to show the real fecundity of the transcendental argument in the field of economics.