THE FATE OF ANALYSIS, #4–Husserl, Pure Logic, & The Sins of Logical Psychologism.

By Robert Hanna



II. Classical Analytic Philosophy

II.1 What Classical Analytic Philosophy Is: Two Basic Theses

II.2 What Classical Analytic Philosophy Officially Isn’t: Its Conflicted Anti-Kantianism

II.3 Classical Analytic Philosophy Characterized in Simple, Subtler, and Subtlest Ways

II.4 Three Kinds of Analysis: Decompositional, Transformative, and Conceptual

II.5 Frege, The First Founding Father of Classical Analytic Philosophy

II.6 Frege’s Project of (Transformative or Reductive) Analysis

II.7 Frege’s Dead End

II.8 Frege’s Semantics of Sense and Reference, aka Meaning

II.9 Some Biggish Problems For Frege’s Semantics

II.10 Husserl, Logic, and Logical Psychologism, aka LP

II.11 What LP is, and its Three Cardinal Sins

II.12 Husserl’s Three Basic Arguments Against LP

II.13 Has Husserl Begged the Question Against LP? Enter The Logocentric Predicament, and a Husserlian Way Out

II. Moore, Brentano, Husserl, Judgment, Anti-Idealism, and Meinong’s World

III.1 G.E. Moore, the Second Founding Father of Classical Analytic Philosophy

III.2 Brentano on Phenomenology, Mental Phenomena, and Intentionality

III.3 Husserl on Phenomenology and Intentionality

III.4 Moore and the Nature of Judgment

III.5 Moore and the Refutation of Idealism

III.6 Meinong’s World

IV. Russell, Unlimited Logicism, Acquaintance, and Description

IV.1 Russell Beyond Brentano, Husserl, Moore, and Meinong

IV.2 Russell and Mathematical Logic versus Kant

IV.3 Russell’s Unlimited Logicist Project

IV.4 Pursued by Logical Furies: Russell’s Paradox Again

IV.5 Russell’s ‘Fido’-Fido Theory of Meaning

IV.6 Knowledge-by-Acquaintance and Knowledge-by-Description

IV.7 Russell’s Theory of Descriptions

IV.8 Russell’s Multiple-Relation Theory of Judgment

IV.9 Russellian Analysis, Early Wittgenstein, and Impredicativity Again

IV.10 Russell and The Philosophy of Logical Atomism

V. Wittgenstein and the Tractatus 1: The Title, and Propositions 1–2.063

V.1 A Brief Synopsis of the Tractatus

V.2 The Tractatus in Context

V.3 The Basic Structure of the Tractatus: A Simple Picture

V.4 Tractarian Ontology

V.5 Reconstructing Wittgenstein’s Reasoning

V.6 What Are the Objects or Things?

V.7 The Role of Logic in Tractarian Ontology

V.8 Colorless Objects/Things

V.9 Tractarian Ontology, Necessity, and Contingency

V.10 Some Initial Worries, and Some Possible Wittgensteinian Counter-Moves

VI. Wittgenstein and the Tractatus 2: Propositions 2.013–5.55

VI.1 What is Logical Space? What is Real Space?

VI.2 Atomic Facts Necessarily Are in Manifest or Phenomenal Space, But Objects or Things Themselves Necessarily Aren’t in Manifest or Phenomenal Space

VI.3 Logical Space is Essentially More Comprehensive than Manifest or Phenomenal Space

VI.4 Why There Can’t/Kant Be a Non-Logical World

VI.5 A Worry About Wittgenstein’s Conception of Logic: Non-Classical Logics

VI.6 What is a Tractarian Proposition?

VI.7 Naming Objects or Things, and Picturing Atomic Facts

VI.8 Signs, Symbols, Sense, Truth, and Judgment

VI.9 Propositions Again

VI.10 Language and Thought

VII. Wittgenstein and the Tractatus 3: Propositions 4–5.61

VII.1 The Logocentric Predicament, Version 3.0: Justifying Deduction

VII.2 The Logical Form of Deduction

VII.3 Logic Must Take Care of Itself

VII.4 Tautologies and Contradictions

VII.5 What is Logic?

VII.6 Logic is the A Priori Essence of Language

VII.7 Logic is the A Priori Essence of Thought

VII.8 Logic is the A Priori Essence of the World

VIII. Wittgenstein and the Tractatus 4: Propositions 5.62–7

VIII.1 Tractarian Solipsism and Tractarian Realism

VIII.2 Tractarian Solipsism

VIII.3 Tractarian Realism

VIII.4 Is the Tractatus’s Point an Ethical One?

VIII.5 The Meaning of Life

VIII.6 Three Basic Worries About the Tractatus

VIII.7 Natural Science and the Worry About the Simplicity of the Objects or Things

VIII.8 Natural Science and the Worry About the Logical Independence of Atomic Facts

VIII.9 Tractarian Mysticism and the Worry About Metaphilosophy

IX. Carnap, The Vienna Circle, Logical Empiricism, and The Great Divide

IX.1 Carnap Before and After the Tractatus

IX.2 Carnap, The Vienna Circle, and The Elimination of Metaphysics

IX.3 The Verifiability Principle and Its Fate

IX.4 The Davos Conference and The Great Divide

X. Wittgenstein and the Investigations 1: Preface, and §§1–27

X.1 From the Tractatus to the Investigations

X.2 The Thesis That Meaning Is Use

X.3 A Map of the Investigations

X.4 The Critique of Pure Reference: What the Builders Did

XI. Wittgenstein and the Investigations 2: §§28–242

XI.1 The Picture Theory and the Vices of Simplicity

XI.2 Wittgenstein’s Argument Against The Picture Theory: A Rational Reconstruction

XI.3 Understanding and Rule-Following

XI.4 Wittgenstein’s Rule-Following Paradox: The Basic Rationale

XI.5 Wittgenstein’s Rule-Following Paradox: A Rational Reconstruction

XI.6 Kripkenstein’s Rule-Following Paradox: Why Read Kripke Too?

XI.7 Kripkenstein’s Rule-Following Paradox: A Rational Reconstruction

XI.8 How to Solve The Paradox: Wittgenstein’s Way and Kripkenstein’s Way

XI.8.1 Wittgenstein and The Rule-Following Paradox: A Rational Reconstruction

XI.8.2 Kripkenstein and The Rule-Following Paradox: A Rational Reconstruction

XII. Wittgenstein and the Investigations 3: §§242–315

XII.1 What is a Private Language?

XII.2 The Private Language Argument: A Rational Reconstruction

XII.3 Is Wittgenstein a Behaviorist? No.

XII.4 Wittgenstein on Meanings, Sensations, and Human Mindedness: A Rational Reconstruction

XIII. Wittgenstein and the Investigations 4: §§316–693 & 174e-232e

XIII.1 Linguistic Phenomenology

XIII.2 Two Kinds of Seeing

XIII.3 Experiencing the Meaning of a Word

XIII.4 The Critique of Logical Analysis, and Logic-As-Grammar

XIV. Coda: Wittgenstein and Kantianism

XIV.1 World-Conformity 1: Kant, Transcendental Idealism, and Empirical Realism

XIV.2 World-Conformity 2: Wittgenstein, Transcendental Solipsism, and Pure Realism

XIV.3 World-Conformity 3: To Forms of Life

XIV.4 The Critique of Self-Alienated Philosophy 1: Kant’s Critical Metaphilosophy

XIV.5 The Critique of Self-Alienated Philosophy 2: Wittgensteinian Analysis as Critique

XV. From Quine to Kripke and Analytic Metaphysics: The Adventures of the Analytic-Synthetic Distinction

XV.1 Two Urban Legends of Post-Empiricism

XV.2 A Very Brief History of The Analytic-Synthetic Distinction

XV.3 Why the Analytic-Synthetic Distinction Really Matters

XV.4 Quine’s Critique of the Analytic-Synthetic Distinction, and a Meta-Critique

XV.5 Three Dogmas of Post-Quineanism

XVI. Analytic Philosophy and The Ash-Heap of History

XVI.1 Husserl’s Crisis and Our Crisis

XVI.2 Why Hasn’t Post-Classical Analytic Philosophy Produced Any Important Ideas in the Last Thirty-Five Years?

XVI.3 On Irad Kimhi’s Thinking and Being, Or, It’s The End Of Analytic Philosophy As We Know It (And I Feel Fine)

XVI.4 Thinking Inside and Outside the Fly-Bottle: The New Poverty of Philosophy and Its Second Copernican Revolution


This installment contains sections II.10 — II.11.

But you can also read or download a .pdf version of the complete book HERE.


II.10 Husserl, Logic, and Logical Psychologism, aka LP

Edmund Husserl (1859–1938)

According to Edmund Husserl in his 1901 philosophical blockbuster, the Prolegomena to Pure Logic, which constitutes the preliminary rational foundation for — and also the entire first volume of — his equally blockbuster Logical Investigations, pure logic is the a priori theoretical, nomological science of “demonstration” (LI 1, 57; Hua XVIII, 23).[i]

For him, demonstration includes both consequence and provability.

Consequence is the defining property of all and only formally valid arguments, i.e., arguments that cannot lead from true premises to false conclusions.

And provability, aka “completeness,” is the property of a logical system such that, for every truth of logic in that system, there is, at least in principle, a rigorous step-by-step logically valid procedure demonstrating its validity according to strictly universal, ideal, and necessary logical laws.

In this way, the laws of pure logic completely determine its internal structure.

Moreover, these laws and these proofs are all knowable a priori, with self-evident insight (LI 1, 196; Hua XVIII, 185–195).

So not only is pure logic independent of any other theoretical science, in that it requires no other science in order to ground its core notion of demonstration, it also provides both epistemic and semantic foundations for every other theoretical science, as well as every practical discipline or “technology.”

To the extent that pure logic is the foundation of every other theoretical science, it’s the “theory of science” or Wissenschaftlehre in Bolzano‘s sense of that term (LI 1, 60; Hua XVIII, 27), the “science which deals with the ideal essence of science as such” (LI 1, 236; Hua XVIII, 244), and thus the science of science.

Logical Psychologism, or for convenience, LP, is a particularly strong version of the denial that pure logic is an independent and absolutely foundational science.

LP was a widely held view in the second half of the 19th century that grew out of the neo-Kantian and neo-Hegelian traditions alike, and it’s also closely associated with the origins of empirical psychology as an autonomous discipline.[ii]

Husserl’s arguments against LP in chapters 1–8 of the Prologemena, often referred to simply as Husserl‘s “refutation” of LP, constitute one of the most famous and broadly influential critical set-pieces in 20th century philosophy, comparable in these respects to W.V.O. Quine‘s famous attack on the analytic-synthetic distinction in “Two Dogmas of Empiricism,” published almost exactly fifty years after the Prolegomena.

In this connection, it’s surely by no means a historical or philosophical accident that the original working title of another one of Quine‘s famous and closely-related essays from the same period was “Epistemology Naturalized: Or, the Case for Psychologism.”[iii]

By the 1950s, psychologism was making a serious comeback in epistemology, if not in the philosophy of logic.

But radically unlike Quine‘s seminal essays,[iv] which are still widely read, studied, and taught in contemporary Anglo-American and European Analytic-philosophy-oriented departments of philosophy, Husserl‘s Prolegomena nowadays is rarely read or studied, and even more rarely taught.

Insofar as the debate between LP and anti-psychologism is still an issue, moreover, it’s Frege’s logico-philosophical writings that Analytic philosophers take to be the seminal texts on anti-psychologism.

It’s obvious that Husserl‘s conception of pure logic shares much with Frege‘s conception of pure logic in his 1879 Begriffsschrift and other manuscripts he was working on in the 1880s and 90s,[v] even allowing for differences in the formal details of their logical theories.

It’s also obvious that Husserl‘s critique of LP shares much with Frege’s critique of LP in his 1884 Foundations of Arithmetic and the Forward of his 1893 Basic Laws of Arithmetic, and that there’s a direct, important, influential relationship between Frege’s devastating 1894 review of Husserl‘s Philosophy of Arithmetic,[vi] and Husserl‘s lengthy and passionate defense of his conception of pure logic against LP.

Indeed, this is all explicitly conceded by Husserl in the second half of an unintentionally ironic footnote buried away almost exactly in the middle of the Prolegomena (LI 1, 179, n.**; HUA XVIII, 169, n. **).

But whatever the precise nature of Frege’s influence on Husserl himself, and whatever the contemporary status of Frege’s anti-psychologistic writings, Husserl’s arguments against LP in chapters 3–8 of the Prolegomena are independently philosophically interesting; and in fact they had a massively greater intellectual and professional impact on the development of German and European philosophy in the first half of the 20th century, than Frege‘s arguments did.[vii]

Moreover, and perhaps most importantly, as we’ll see in sub-section II.13 below, one of the deepest problems in the philosophy of logic arises directly from Husserl’s arguments against LP.

Husserl’s two-part response to this deep problem offers a prima facie compelling line of argument to which contemporary philosophers of logic and philosophical logicians should pay close attention.

II.11 What LP is, and its Three Cardinal Sins

the essential theoretical foundations of logic lie in psychology, in whose field those propositions belong — as far as their theoretical content in concerned — which give logic its specific character (Gepräge). (LI 1, 90; HUA XVIII, 63)

In this way, LP is the thesis that logic is reducible to empirical psychology[viii] in the strong, dual (i.e., explanatory and ontological) sense that

(i) a complete knowledge of the empirical, natural facts and causal laws with which empirical psychology deals would yield a complete a priori knowledge of the existence and specific character of logic, and

(ii) the empirical, natural facts and causal laws with which empirical psychology deals strictly determine the existence and specific character of logic.

Or in other words, according to LP, logic is nothing over and above empirical psychology.

This does not entail that empirical psychologists of logic are, in and of themselves, logicians, but instead only that whatever it is that logicians know about logic, can in principle be known by empirical psychologists wholly and solely by virtue of their knowing all the empirical, natural facts and causal laws that are relevant to logical thinking.

Husserl’s presentation of LP proceeds by means of a lengthy and sometimes repetitive critical exposition of the views of the leading recent and exponents of LP, including Mill, Bain, Spencer, Wundt, Sigwart, Erdmann, Lange, Lipps, Mach, and Avenarius.

As against the “psychologicists,” Husserl explicitly aligns himself with Leibniz, Kant, Herbart, Bolzano, Lotze, and (somewhat more covertly, as I noted above) Frege.

In the crucial case of Kant, however, there is some apparent equivocation, when in a footnote Husserl asserts that “even transcendental psychology also is psychology” (LI 1, 122, n.1; HUA XVIII, 102, n. 3).

This apparent equivocation on Husserl’s part can perhaps be explained away by distinguishing between Kant’s theory of logic, which is explicitly and strongly anti-psychologistic,[ix] and some neo-Kantian theories of logic, which are arguably psychologistic.

If this is correct, then Husserl is not really equivocating; instead, he is attributing psychologism to the mere followers, aka “epigones,” of Kant, but not to Kant himself, who would on the contrary be historically and rhetorically aligned with Husserl‘s own anti-psychologism.

Quite apart from the historical and rhetorical vehicle of Husserl‘s critique of LP, however, its underlying content and structure involve, first, a pair-wise contrastive characterization of LP’s conception of logic over and against Husserl‘s own conception of pure logic, and then second, a set of critical arguments showing how LP either fails by external rational standards or internally refutes itself.

The pair-wise contrastive characterization of logic according to LP versus pure logic according to Husserl can be summarized as follows.

Logic according to LP is:

(i) contingent

(ii) based on particulars

(iii) based on empirical facts

(iv) concretely real

(v) governed by causal laws

(vi) conditional

(vii) belief-based

(viii) based on relativized, subjective truth known by sense experience

(ix) a posteriori

(x) empirical

(xi) instrumentally normative

Pure Logic according to Husserl is:

(i*) necessary

(ii*) based on real universals

(iii*) based on non-empirical essences

(iv*) abstractly ideal

(v*) governed by strictly universal laws

(vi*) unconditional

(vii*) truth-based

(viii*) based on absolute, objective truth known by self-evident insight

(ix*) a priori

(x*) non-empirical

(xi*) categorically normative

It should be especially noticed that the items in the first list all differ from the corresponding items in the second list not in degree but rather in kind.

In each pairing, some extra non-natural or ideal property has been added by Husserl to the right-hand item of that pair in order to distinguish it in kind from the corresponding item on the left-hand side.

The extra properties attributed by Husserl to pure logic are “non-natural” or “ideal” in two senses.

First, none of the extra properties is to be found in the physical, spatiotemporal world.

Second, none of the extra properties is knowable by experiential, experimental methods.

So according to Husserl, pure logic is uniquely characterizable in terms of a set of special non-natural or ideal kinds to which LP has no ontological access (since LP has access only to the physical, spatiotemporal world) or explanatory access (since LP has access only to concepts and beliefs that are generated by experiential, experimental methods).

This catalogue of sharply opposed conceptions of logic is then strategically exploited by Husserl in his three basic charges against LP — as it were, the three “cardinal sins” of LP.

Husserl‘s first basic charge against LP is that LP is committed to what I will call Modal Reductionism about Logic or MRL, which says logical laws and logical truths are explanatorily reducible to merely causal laws and merely contingent, probabilistic truths:

The task of psychology is to investigate the laws governing the real connections of mental events with one another, as well as with related mental dispositions and corresponding events in the bodily organism…. Such connections are causal. The task of logic is quite different. It does not inquire into the causal origins or consequences of intellectual activities, but into their truth-content. (LI 1, 93–94; HUA XVIII, 67)

Laws of thought, as causal laws governing acts of knowledge in their mental interweaving, could only be stated in the form of probabilities. (LI 1, 101; HUA XVIII, 76)

Logical laws according to Husserl are necessary rules, and logical truth according to Husserl is necessary truth.

On the classical Leibnizian account, a rule or proposition is logically necessary if and only if it’s true in every “possible world,” i.e., in every total set of “compossible” or essentially mutually consistent substances, insofar as this compossibility is completely envisioned by God.

Sometimes this Leibnizian, or theocentric, type of logical necessity is also called metaphysical necessity.

By contrast, according to the Kantian account, a rule or proposition is logically necessary if and only if it’s “strictly universal” and also “analytic,” that is:

(i) it’s true in a complete class of humanly conceivable variants on the actual experienced world,

(ii) there’s no humanly conceivable variant on the actual experienced world that’s an admissible counterexample to it, and

(iii) its denial entails a contradiction.[x]

Sometimes this Kantian, or anthropocentric, type of logical necessity is also called conceptual necessity.

Otherwise put now, and regardless of whether the necessity is construed as metaphysical necessity (Leibnizian or theocentric logical necessity) or as conceptual necessity (Kantian or anthropocentric logical necessity), logical laws and logical truths, as necessary, are always absolutely or unrestrictedly true.

By sharp contrast, merely causal laws and merely probabilistic laws are inherently restricted by brute facts about the actual world.

As Hume pointed out, there is no absolute guarantee that any causal law, no matter how generally it holds in the actual world of sensory experiences, will always hold.

And mere probabilities, no matter how probable, are always less than 1.

So Husserl‘s first basic charge against LP, or MRL, says that by explanatorily reducing logical laws and logical truths to merely causal laws and merely contingent, probabilistic truths, LP radically restricts the scope of pure logical truth.

Husserl‘s second basic charge against LP is that LP is committed to what I’ll call Epistemic Empiricism about Logic or EEL, which says that logical knowledge is explanatorily reducible to merely a posteriori knowledge:

[According to LP] no natural laws can be known a priori, nor established by sheer insight. The only way in which a natural law can be established and justified, is by induction from the singular facts of experience. (LI 1, 99; HUA XVIII, 73)

On this basis [of LP], no assertion could be certainly judged correct, since probabilities, taken as the standard of all certainty, must impress a merely probabilistic stamp on all knowledge. (LI 1, 101; HUA XVIII, 76)

Logical knowledge according to Husserl is a priori knowledge and also certain knowledge.

A priori knowledge, in turn, is belief that is sufficiently justified by evidence which is underdetermined by all sets and sorts of sensory experiences, possibly also including evidence that includes no sensory experience whatsoever and is rationally “pure.”

Certain knowledge is indubitable belief, i.e., belief that’s not open to refutation by actual or possible counterexamples, and more particularly, it’s not open to refutation by sensory experiences or factual statistics.

So Husserl‘s second basic charge against LP, or EEL, says that LP radically underestimates the epistemic force of pure logical knowledge.

Husserl‘s third basic charge against LP is that it is committed to what I will call Skeptical Relativism about Logic, or SRL, which says that logical laws, logical necessary truth, and logical knowedge are explanatorily reducible to either individually-held beliefs (individual relativism) or species-specific beliefs (specific relativism):

In order to criticize psychologism we have … to discuss the concept of subjectivism or relativism, which is also part of the above-mentioned [skeptical] theory. One of its original forms is caught in the Protagorean formula: “man is the measure of all things,” provided this last is interpreted as saying “The individual man is the measure of all truth.” For each man that is true which seems to him true, one thing to one man and the opposite to another, if that is how he sees it. We can therefore opt for the formula “All truth (and knowledge) is relative” — relative to the contingently judging subject. If, however, instead of such a subject, we make some contingent species of judging beings the pivot of our relations, we achieve a new form of relativism. Man as such is then the measure of all truth. Every judgment whose roots are to be found in what is specific to man, in the constitutive laws of man as species — is a true judgment, for us human beings. To the extent that such judgments belong to the form of common human subjectivity, the term “subjectivism” is in place here too (in talk of the subject as the ultimate source of knowledge, etc.). It is best to employ the term “relativism,” and to distinguish individual from specific relativism. The restriction of the latter to the human species, stamps it as anthropologism. (LI 1, 138; HUA XVIII, 122)

Relativism — or more precisely, cognitive relativism, which is about theoretical beliefs and truth, as opposed to moral relativism, which is about ethical beliefs and principles of conduct — says that truth is determined by belief or opinion.

In turn, there are two distinct types of cognitive relativism.

On the one hand, individual cognitive relativism says that truth is determined by individual beliefs or opinions (= subjective truth).

And on the other hand, specific cognitive relativism or anthropologism says that truth is determined by beliefs or opinions that are either the result of human agreement (= truth by mutual contract, or truth by general convention) or are innately biologically specified in all human beings (= truth by instinct).

According to Husserl, logical truth is objective truth, hence mind-independent truth, hence truth that is inherently resistant to determination by any merely subjective, contractual, conventional, or biological facts.

So Husserl‘s third basic charge against LP, or SRL, says that LP implies a mistaken and indeed ultimately skeptical theory of the determination of truth.


[ii] See, e.g., M. Kusch, M. Psychologism (London: Routledge & Kegan Paul, 1995).

[iii] Kusch, Psychologism, p. 11.

[iv] W.V.O. Quine, “Two Dogmas of Empiricism,” in W.V.O. Quine, From a Logical Point of View, (2nd edn., New York: Harper & Row, 1961), pp. 20–46; W.V.O. Quine, “Epistemology Naturalized,” in W.V.O. Quine, Ontological Relativity, New York: Columbia Univ. Press, 1969), pp. 69–90; W.V.O. Quine, “Truth by Convention,” in W.V.O. Quine, The Ways of Paradox, 2nd edn., Cambridge, MA: MIT Press, 1976), pp. 77–106; and W.V.O. Quine, “Carnap and Logical Truth,” in Quine, The Ways of Paradox, pp. 107–132.

[v] See, e.g., G. Frege, “Logic [1897],” in G. Frege, Posthumous Writings, trans. P. Long et al. (Chicago, IL: Univ. of Chicago Press, 1979, pp. 127–151.

[vi] G. Frege, “Review of E. G. Husserl, Philosophie der Arithmetik I,” in G. Frege, Collected Papers in Mathematics, Logic, and Philosophy, trans. M. Black et al. (Oxford: Blackwell, 1984), pp. 195–209.

[vii] See, e.g., Kusch, Psychologism, chs. 1, 3, 4.

[viii] See, e.g., R. Hanna, Rationality and Logic (Cambridge, MA: MIT Press, 2006), ch. 1, also available online in preview, HERE.

[ix] R. Hanna, Kant and the Foundations of Analytic Philosophy (Oxford: Clarendon/Oxford Univ. Press, 2001), pp. 71–76, also available online in preview, HERE.

[x] Hanna, Kant and the Foundations of Analytic Philosophy, chs. 3 and 5.


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