To understand why academic philosophy in the dubiously titled “West” is divided between the so-called “Continental” and “Analytic” traditions, it is best to start with a rather esoteric debate concerning the origin of number. It is a strange history in which such a topic introduces a wedge that so bitterly divides a discipline, but one that is worth considering for both its philosophical and sociological significance. The two parties in this encounter are Gottlob Frege (1848-1925), from whom I trace the lineage of the Analytic style, and Edmund Husserl (1859-1938), the founder of phenomenology as a rigorous method whose influence is largely responsible for the development of Continental philosophy is its various forms as it responded to, adapted, and rejected parts of Husserl’s phenomenological project.

While it is true that Continental philosophy has its affinities with Nietzsche and Kierkegaard, a stronger continuity with German Idealism following Kant and Hegel, I find that the disputation between Frege and Husserl is the real starting point for the division between the Analytics of the Anglo-American and Australian schools and the Continental modes of philosophizing in the German and French speaking world, which is variously celebrated or condemned in the English speaking world.
…Husserl maintains a position in which we cannot completely separate questions about extant things which may have mind-independent existence from the ways in which us minded creatures come to know about the being of such plausibly mind-independent entities.
The key issue that unites these thinkers is a rejection of psychologism concerning logic. Here “psychologism” is an account of logic and its derivatives as purely psychological phenomenon; the laws of logic are just the psychological “laws of thought” by which humans reason and are therefore not mind independent or otherwise objective laws inhering in nature. The arguments that brought Frege and Husserl together are expressed by the latter in his early work on the foundations of mathematics and the origin of number called Philosophie der Arithmetik (1891), translated as Philosophy of Arithmetic. In that book, Husserl offers an account of the origin of number that, for Frege, veered too close to psychologism. I do not interpret Husserl to be advocating psychologism in that early text, however, it seems clear that because he had not yet developed the phenomenological vocabulary for which he became known and which answer the problems raised by Philosophy of Arithmetic, the early Husserl lends himself to confusion concerning a distinction between the ontological status of mathematical objects and the psychological processes by which we come to know and think about those objects. That being said, it remains the case that Husserl maintains a position in which we cannot completely separate questions about extant things which may have mind-independent existence from the ways in which us minded creatures come to know about the being of such plausibly mind-independent entities.
The problem occurs when Husserl attempts to show how we derive the idea of number from experience, abstracting from an experience of something in order to form the more general concept of a “unit” in the mathematical sense of a numeral. Thus, the “origin” here is the origin of an idea and constitutes a claim that tends toward epistemology over ontology. The confusion arises when Husserl’s underdeveloped language allows for a reading in which the concept of number, at which we arrive through abstraction from experience, is nothing other than the psychological process of abstraction from experience that forms the concept. This is not an acceptable account of the real number because, as Frege objects, number is not dependent upon our mental processes, but is rather something actually extant which is discovered through the use of reason.
Frege had already established a view on the ontological status of numbers when Husserl published Philosophy of Arithmetic in 1891. In Frege’s Die Grundlagen der Arithmetik (1884), translated as The Foundations of Arithmetic, a theory of number is posited wherein numbers are neither physical nor mental objects but are purely formal concepts. Such purely formal concepts are distinct from objects in that they are a special kind of function which occur as second order predicates of other concepts. These second order predicates do not pick out properties such as when we say “the light is green” to indicate that the object “light” has the property of “being green”, but rather indicate that some concept is instantiated a certain number of times, such as when I say that “there are two apples,” I mean to indicate that some object falling under the concept of “apple” is occurring two times — is instantiated twice, once in each of the two objects I call “apple.” Frege makes this move to avoid both an empirical account of number associated with John Stuart Mill, while also allowing him to deny Kant’s claim that number is a synthetic a priori. For Frege, unlike Kant, number must be analytic, not synthetic.
Frege’s idea rests upon an axiom involving a (1, 1) correspondence. If we can show that some set of objects share the property of “same number,” regardless of the specific number of things in each set, the concept of number itself can be defined on the basis of this property. This start, taken from the (1, 1) correspondence, is expressed by Frege’s idea of the “equi-numerous.” For example, we could say that there are some apples on the table and that each apple has a stem. So we have two sets, the set of apples and the set of stems each set having the same number of members. Given the (1, 1) correlation, we can then define the property of “having the same number” without reference to numbers. The way it works out, the claim that “there are 2 apples on the table” is a first-order concept which then falls under the second-order concept of being “a concept under which two objects [the apples] fall.” Circularity is avoided because, as Frege argues, the second-order concept does not itself make any appeal to the concept of “two” as the first-order concept does. Instead, the second-order concept simply fulfills a formal condition, namely, the condition that there be distinct objects, x and y, which both fall under the concept F and any object falling under the concept F is identical to x or y.
Continental philosophy is synthetic; Analytic philosophy is reductive.
It should be clear, given the formal nature of Frege’s account, why he would take exception to Husserl’s arguments concerning the origin of number as an abstraction from experience. However, Husserl’s vision is much broader than Frege’s and this feature marks a key distinction between Analytic and Continental philosophy generally. Continental philosophy’s range of vision is broad and it seeks connections across a wide range of domains. Continental philosophy is synthetic; Analytic philosophy is reductive.
Consider the fact that two of Husserl’s acknowledged mentors are Franz Brentano, the champion of empirical psychology, and Karl Weierstrass, the great mathematician who provided the proof for the intermediate value theorem among many other notable achievements. These influences give some indication why Husserl remains committed to the connections between reality and the way in which what is real appears to us. Any discussion about mathematics, reference, meaning, or significance is always held against the backdrop of a larger picture concerning conscious experience.
Husserl respects Frege, but holds reservations about the formal account of the foundations of arithmetic he offers. For Husserl, it was important that we be able to account for how and why it is possible for us to think about mathematics in the way that we do. This concern is Kantian — what are the conditions of the possibility of mathematical thinking? But notice that this should also tell us something about the things we think about if those things are to be possible objects of thought. If we think about them, they must be discernible in thought. The way we think about them, they way in which they appear to us, should therefore provide an inroad to the thing itself since its structure is such that it lends itself to being discerned in the first place. Herein lies the basic idea behind Husserl’s later phenomenological credo “to the things themselves!” What Frege’s account could not do is explain how or why we could think about and conceive of number in the way that we do and it certainly did not lead us to reproduce the mental processes necessary for the construction of the concepts for ourselves. Later, Husserl will expect that phenomenological investigation would permit such reproduction.
Notice too that, given the argument above, Frege still seems to be arriving at the concept of number through a process attentive to the way in which things are given in appearance. His arguments follow a pattern in which they work through propositions about things which appear in like sets and so on to reach conclusions concerning a pure principle of logic. The conclusions are just a matter of formalizing the outcomes of the process such that the ultimate concept is emptied of its particularity.
Whatever Husserl’s reservations regarding Frege’s theory of number, in 1891 Husserl sends Frege a review of the first volume of Ernst Schröder’s Vorslesungen über die Algebra der Logick (1890), or Lectures on the Algebra of Logic. Ironically, the ensuing correspondence did not explicitly touch on the theme of psychologism. Instead, we find Frege’s first letter expounding on sense and reference in response to Husserl’s own system of sense-reference outlined in the works he sends to Frege. Upon closer consideration, this emphasis on sense and reference is not quite so out of place in a disputation on psychologism. Husserl’s theory of number demanded that number as a concept be treated as the content of a presentation or act. Indeed, all concepts were the contents of the acts by which they were presented to conscious experience. This is unacceptable to Frege, because he viewed concepts as objective, whereas presentations were relegated to the private, subjective sphere of particular thinkers. But this throws a wrench into the gears of Husserl’s fundamental conviction that philosophy should be primarily focused on analyzing experience. It becomes apparent that such a focus risks reducing philosophy to studying what is merely subjective. That prospect is unacceptable to Husserl, who still maintains a commitment to attaining knowledge that is objective and non-relativistic.
This exchange highlights a fundamental difference between Analytic and Continental philosophy wherein Analytic philosophers remain stuck on Frege’s initial criticism of Husserl. Among the most common dismissals of Continental philosophy by Analytic philosophers is merely some variation of Frege’s charge that Continental philosophy results in subjectivism or some sort of relativism. This accusation may be second only to the charge that Continental philosophy is obscurantist non-sense. I will not address this latter charge in detail at this time, except to say that Continental philosophy has a technical vocabulary just as Analytic philosophy does and if Analytic philosophers find each other to be more clear it is only because they are familiar with their own technical jargon, which is taken for granted as they sling mud at thinkers whose vocabulary is not properly understood.
All consciousness is consciousness of… something. Experience is about things.
Be that as it may, Husserl recognizes that a non-psychological account of content is necessary if he is to establish that the meaning of concepts are in fact objective and intersubjective. Husserl’s ultimate solution to this problem lies in his transcendental phenomenology.
The path to transcendental phenomenology follows Brentano’s thesis that intentionality is the structure of consciousness. All consciousness is consciousness of… something. Experience is about things. Frege is unhelpful in understanding how we come to grasp the objective sense of things. He more or less asserts that we do grasp it, though the act of understanding has mental existence while the sense of things is objective and intersubjective. According to Frege’s arguments the act, as private and subjective, does not bear an ontological relationship with the objective, public sense. Husserl begins to offer an explanation of their interaction that is much more sophisticated than Frege’s, whose account would have senses relating to acts in almost the same way as do physical objects. This arrangement would have the sense being taken as an object of an act of understanding or apprehension. On this score, it is Frege who offers a confused analysis, since he sometimes seems to be arguing that we grasp the sense of things like we grasp objects, while other times he seems to be saying that the sense of things is a part of the act that enables us to apprehend the object as meaningful in the first place. Husserl’s adaptation of intentionality into his analysis provides a more lucid explanation of the relation between sense and act in addition to a wide-ranging, he claims universal, set of relationships between cognition and its objects.
In any event, it is evident that Husserl saw for himself the potential for psychologistic misunderstanding of his early work on the foundations of mathematics and he took Frege’s critical review of Philosophy of Arithmetic seriously. These exchanges, together with his own reservations, lead Husserl to open his Logische Untersuchungen (1900), or The Logical Investigations, with an extended refutation of psychologism.
All formal principles permit a normative transformation, but are not in themselves normative.
I want to focus in on Sections 41-51 of the “Prolegomena” in The Logical Investigations, where Husserl points out three “prejudices” of psychologism that his Investigations avoid.
The first is that laws regulating mental phenomena must be themselves founded in the mental. From this prejudice, it follows that any normative principle of knowledge would find its basis in the psychology of knowledge. Responding to this first prejudice, Husserl makes a remark to the effect that we abandon general argumentation in order to turn “to the things themselves.” What this turn reveals is that logical laws are not normative propositions such that they dictate how one ought to think. To be sure, it is a rule that if every object which has the property A also carries property B, and if a given object S also has the property A, then it also as the property B, but this rule is far from normative in itself, though it can be deployed for normative ends. Normativity is not native to the rule, but is introduced when we assert that if one judges that every A is also a B, and we know that S is an A, then we should conclude that S is a B. Husserl uses this example as well as the mathematical statement that (a+b)(a-b) = a²-b² to show us that such a rule, that the product of the sum of any two numbers and the difference of those two numbers is equal to the difference of their squares, is not normative unless we want to know either side of the equation. Then, we can apply the rule normatively as when we say, if you want to know the difference in the squares of two numbers, then you should multiply the sum of the numbers by their difference. All formal principles permit a normative transformation, but are not in themselves normative.
The second prejudice involves a move that serves to support the first prejudice by an appeal to the content of logic rather than its formal character. Logic is about presentations, judgments, syllogisms, proofs, truth, falsity, probability and necessity, and so on. But this again mistakes the application of formal rules in the temporal processes of thinking undertaken by an individual. Pure mathematical and logical principles are not to be confused with the cognitive processes which make use of them in thinking about particular logical or mathematical problems, arguments, or what have you. At this point, Husserl points readers to two works by Frege, The Foundations of Arithmetic and the first volume of Frege’s later masterwork Die Grundgesetze der Arithmetik (1893), now in translation as The Basic Laws of Arithmetic. In this approving nod to Frege, Husserl walks back his earlier criticisms of Frege’s anti-psychologism, which Husserl had put forth in Philosophy of Arithmetic. It is clear that Husserl’s transcendental turn is in agreement with Frege over the ideal status of logical laws. However, Husserl still maintains, just as he had in Philosophy of Arithmetic, that when we do properly conceive of the purely formal principles of logic, we do so by a presentation through which we work to arrive at the formal principle.
Finally, the third prejudice involves the problem of evidence. Psychologism maintains that truth pertains to judgment, and such judgments are subjective, which means that we recognize a judgment to be true only by way of inner evidence. “Inner evidence” carries a mental character — essentially a feeling which guarantees the truth of the judgment, leading to our certainty in the judgment’s truth. Husserl’s refutation brings together the threads he began when objecting to the first prejudice. Logical principles are just not about anyone’s judgment, though they may be used in judgments and direct them toward truth. That (a+b) = (b+a), as Husserl illustrates, does not claim anything about our judgment of a proposed calculation such as when I judge that (2+5) = (5+2), both sums being 7. Again, I have applied the law in a psychological process of calculating the sums, but the rule itself contains nothing nor makes reference in any way to this act itself. The principle is a pure one which facilitates judgment, a priori, by application of the principle to particular numbers.
Truth, for Husserl, is an Idea and we experience particular truths as inwardly evident judgments.
Husserl attempts to clear up these confusions by a rigorous distinction between the real and the Ideal, where “inner evidence” is not a feeling one has that clues one into the fact that a judgment is true. Rather, such inner evidence is nothing but the experience of the true. Truth, for Husserl, is an Idea and we experience particular truths as inwardly evident judgments. Inner evidence is understood as a correspondence, as an experience of the agreement between the meaning of our concepts and what is presented to us in experience; experience always being a cognitive act. Another way to say this is that we recognize truth by experiencing an agreement between the sense of an assertion and a given state of affairs. The Idea of such an agreement, according to Husserl, is truth, the very objectivity of which is precisely its ideality.
His refutation of psychologism, exemplified here in the analysis of three prejudices outlines above, show that Husserl is committed to a deep exploration of the relations between the being of ideal, mind-independent formal principles and the ways in which those principles appear to us as we experience them, know about them, and deploy them for practical and normative ends within our psychological processes. This feature of Husserl’s burgeoning phenomenology becomes a centerpiece of Continental philosophy broadly construed as Husserl begins to attract students such as Edith Stein, Max Scheler, and Martin Heidegger. The refutations of psychologism are widely discussed in the German speaking world and Husserl also attracts critics from among Neo-Kantians such as Paul Natorp and the Vienna Circle, notably Moritz Schlick.
It is the combined influence of the Vienna Circle and Frege that help foster early Analytic philosophy’s allergy to Husserl’s phenomenological analysis of the structures of experience, as well as the progress being made in mathematical logic by Bertrand Russell. Frege himself plays a part in encouraging Wittgenstein to go to Cambridge, and Wittgenstein’s Tractatus is widely discussed by the Vienna Circle, though it’s arguments remain mysterious to Frege who seems bent on persuading Wittgenstein to take up the project of the Grundgesetze as his own. Frege experienced a series of late career frustrations, most significantly in his 1902 correspondence with Russell, where Russell alerts Frege of a contradiction in the system of the Grundgesetze now famous as Russell’s Paradox. Interestingly, Ernst Zermelo had come upon the paradox independently of Russell and had shared his findings with other figures at the University of Göttingen, including Husserl. The knowledge of the paradox may have helped to persuade Husserl, perhaps preemptively, away from quantificational logic. This influence on Husserl may also help explain why the phenomenological “pure theory of manifolds” seems to prefigure model theory in striking ways. These considerations are topics for another time.
Indeed, reductionism and eliminative materialism in Analytic philosophy of mind represent the apotheosis of Continental thought in that they attempt to eliminate the very dimension of human experience opened by phenomenological analysis.
In terms of the Continental-Analytic divide, a few concluding remarks based upon the arguments presented above are in order. Husserl provides a synthetic model for Continental philosophy, which fuses purely formal analysis with serious consideration of the way in which those formal elements occur in experience. Continental philosophy, insofar as it inherits Husserl’s projects, will always concern itself with both the world as it might be in itself and with the way in which that world manifests itself to human beings who are trying to find their place in that world. Analytic philosophy, taking after Frege and the Vienna Circle, increasingly attempts to downplay the role of subjective experience in their analysis of the mind-independent world. Indeed, reductionism and eliminative materialism in Analytic philosophy of mind represent the apotheosis of Continental thought in that they attempt to eliminate the very dimension of human experience opened by phenomenological analysis. To be sure, what is eliminated by these theories is a highly idiosyncratic understanding of the subjective that is foreign to Husserl and those who follow him — so highly idiosyncratic that it sometimes appears as if those objects were invented for the sole purpose of being eliminated. The death of the subject heralded by Continental thinkers is in no way connected to the Analytic reductions and is more fundamentally aligned with understanding the history of ideas and the theological roots of the modern conception of subjectivity. Analytic philosophy will largely come to eschew a serious engagement with the history of ideas.
While these agreements and disputes between Husserl and Frege provide a seedbed for the distinction between Continental and Analytic philosophy, those seeds really begin bearing fruit when Heidegger takes over the mantle of phenomenology in Sein und Zeit (1927). That notorious, provocative treatise establishes a fundamental divergence between two traditions, which, both in their own ways, are committed to figuring out how to do philosophy after the death of metaphysics, which Husserl himself saw clearly at the end of his career.