method. If the art—τέχνη (technē)—of thinking is based on our psychological makeup, or, as Husserl puts it, is “a psychologistically determined technology of correct thinking,”35 then judgments become a set of relativistic propositions, lacking any firm basis against which we can discriminate as to which statements are true and which are not.
At the beginning of Logical Investigations, Husserl observes that doctrines put forward by representatives of psychologism—which for Husserl is skepticism and relativism at its worst—amount to nothing less than “bellum omnium contra omnes” (LI, § 1, 11).36 Reason is reduced to our experience here and now and explained on the empirical basis only. As a consequence, there is no independent foundation that can serve as the ground for evaluation of our different claims about the world. Any and every opinion is declared “true,” leading to a war of all against all, because if all claims are supposedly correct, there is no possibility whereby we might “separate individual conviction from universally binding truth.” If experience is all that is left to us, there is nothing to guide us toward the truth of our assertions. The normative character of our reasoning cannot be based on temporal experience because this experience is relative to our situation here and now. For Husserl, then, the initial motive for the critique of knowledge must be to revisit “questions of principle”—this “task [. . .] must ever be tackled anew” (LI, § 2, 12).
PHILOSOPHY OF ARITHMETIC
In Philosophy of Arithmetic, Husserl’s first book, he is concerned with the concepts, such as “unity, multiplicity and number,” that are “fundamental to human knowledge on the whole” (14). As he notes, since these concepts are not established clearly, they give rise to “the considerable difficulties that accrue to their understanding,” thereby instituting “dangerous errors and subtle controversies” (PA, 14). He cautions that we need to inquire into the foundation of knowledge by making clear to ourselves the basic presuppositions from which our claims proceed (ILI, § 12, 59). Only “through patient investigation of details” can we become aware of the foundations that our knowledge is based on (PA, 5; ILI, § 6, 33–34). For Husserl, “if we are not to be shattered on the rocks of extreme scepticism” (LI, § 6, 17), the path of “painstaking criticism” (PA, 5) must be traveled repeatedly (LI, § 3, 13).
As already noted, Philosophy of Arithmetic is based on “psychological researches,” because Husserl starts from the prevailing assumption of his age that “psychology [is] the science from which logic in general and the logic of the deductive sciences had to hope for philosophical clarification.” Yet he had begun to doubt the reigning wisdom of his time, according to which logic was reduced to psychology. As he says, “Such a psychological foundation never came to satisfy me” (LI, § 2). Gottlob Frege’s review of Husserl’s book reaffirmed his already changed understanding.37 The announced second volume of Philosophy of Arithmetic was never published.
It would be erroneous, however, to assume that Husserl’s first book is unconnected to his later work. Already in Philosophy of Arithmetic, Husserl shows that science can proceed, and proceed well, even though the foundational basis on which science rests is overlooked, or even forgotten. As he cautions, this state of affairs will eventually give rise to problems. In the first instance, this realization leads Husserl to question those beliefs that conflate logic and psychology. Thus Husserl turns to the problem of psychologism38 and anthropologism.
It is imperative to remember that Husserl (along with Frege) attacks “logical psychologism.”39 In Germany, the appeal to psychologism, as Jitendra Nath Mohanty explains, had probably first been made by Benno Erdmann. For Erdmann, psychologism is the “thesis that the logical principles such as the principle of non-contradiction derive their necessity from ‘the essence of our presentation and thinking.’”40 As Heidegger also explains, “‘Psychologism’ expresses the priority of psychology, particularly with regard to logic and its project.”41
THE SPECTER OF PSYCHOLOGISM
Opiates suppress the symptoms; they do not cure the disease. (ILI, § 2, 23)
At the beginning of Logical Investigations, Husserl suggests a parallel between the artist’s and the scientist’s activity. While the artist performs or creates his art, he can only rarely account for the rules by which it is framed. He is simply the master of “technique” acquired through practice, and his judgment is related to his activity as an artist (LI, § 4, 15). If we take art in its broad sense, as the ancient Greeks did, then we are thinking of technē. This assessment, then, also applies, generally speaking, to science. So, while doing research, the scientist does not need to reflect on the rules that are constitutive of science, but follows her knowledge, instinct, and observations, which she has acquired through her training as a scientist: “Even the mathematician, the physicist and the astronomer need not understand the ultimate grounds of their activities in order to carry through even the most important scientific performances” (LI, § 4, 15). There is nothing surprising about the fact that scientists are not expected to perform validations all the time. Yet the danger is that they become “lost in an excessive symbolism” (FTL, § 33, 98). Husserl draws attention to the scientific practice in which, in order to “economize thought,” scientists use “abbreviations and substitutes,” instead of going back to the basic axioms on which scientific knowledge is based (LI, § 9, 23; italics in original). By privileging the so-called need “for greater exactness,” theory is substituted with “its symbolic analogue.” In short, theory is defined “in terms of mere rules of the game” (FTL, § 34, 100). As Husserl sums up, “The incomplete state of all sciences depends on this fact”; that is, on ignorance of the foundational basis from which science has evolved. He insists that sciences stand in need of “inner clarity and rationality” (LI, § 4, 15).
To be sure, this lack of understanding did not slow the growth of science, bringing about “a formerly undreamt of mastery over nature”; however, this kind of science “cannot satisfy us theoretically” (LI, § 4, 16). We need to account for the metaphysics presupposed by the notions that “an external world exists” and “is spread out in space and time”; that space is mathematical and “three-dimensional and Euclidean, and its time [is] a one-dimensional rectilinear manifold; that all process is subject to the causal principle etc” (LI, § 5, 16). These metaphysical notions migrated from Aristotle’s Metaphysics into epistemology. Without any further reflection on the problematic nature of these assumptions, these notions—now taken as belonging to the positive sciences—are understood as “reality” (LI, § 5, 16). The result is a “physicalism” that has forgotten its own metaphysical ground.42
As Husserl elaborates later, to believe in one of the forms of naturalism, physicalism, or positivism is to believe that the world is “the universe of realities in the form of mutual exteriority.” It is to hold that nature is nothing else but “the realm of the pure res extensae” where “every body [stands] under rules of general causality.”43 Moreover, the law of causality is presumed to govern physical as well as psychical processes. This is the metabasis that Husserl is concerned with. Yet a simple reflection reveals that the law of causality cannot be found in the world. It is a formal law, which guides our scientific (that is, empirical) understanding. It is prior to our understanding of nature, and it structures our understanding of nature as “the realm of the pure res extensae.” As Husserl says in Crisis, “The rationality of the exact sciences is of a piece with the rationality of the Egyptian pyramids.”44
In order to understand Husserl’s charge, let us turn our attention to his Logical Investigations. In doing so, we need to keep in mind that, in LI, he presents “a new foundation of pure logic and epistemology”;45 furthermore, according to his later explanation, the LI is not concerned with the “cognition
