A Walk Through the Work’s Arguments on the Foundations and Functions of Conceptual Thought
Chapter I: The Problem of Categories
We are at the opening of the work, where MacIntyre establishes the central philosophical problem that will occupy the entire inquiry: how do we understand the nature and function of categories in human thought and language? This section serves as the initial orientation, laying out the historical and conceptual terrain.
MacIntyre begins by noting that the term “category” has a long and contested history in philosophy, originating with Aristotle’s attempt to classify the fundamental kinds of being. The core problem, he argues, is that categories are not merely arbitrary classifications but are deeply embedded in how we perceive, reason about, and act within the world. He writes: “The problem of categories is the problem of how to classify the most general kinds of things that there are, and the most general kinds of statements that we can make about them.” This dual focus — on ontology and on language — is crucial. Categories are not simply a topic for metaphysicians; they are inescapably tied to how we use concepts in everyday and scientific discourse.
MacIntyre then traces a brief genealogy of the problem. Aristotle’s ten categories (substance, quantity, quality, relation, place, time, posture, possession, action, passion) were an attempt to list the highest genera of beings, but they also served to structure the predicates we attach to subjects in sentences. This ancient model, however, was not taken as final. The modern philosophical tradition, especially through Kant, transformed the problem: categories became not features of the world independently of mind, but a priori forms of understanding that structure all possible experience. MacIntyre emphasizes that Kant’s shift brought a new tension: if categories are imposed by the mind, how can we be sure they correspond to reality? The work will therefore examine both the Aristotelian and Kantian inheritances, but also the ways they have been challenged and revised in subsequent philosophy.
The significance of this opening section is that it frames the entire investigation as one about the relationship between thought, language, and reality. MacIntyre does not here offer a solution. Instead, he insists that the problem of categories is unavoidable: any attempt to understand human knowledge, conceptual change, or the nature of rationality must confront it. “We cannot avoid categorizing,” he says, “but we can reflect on the categories we use.” That act of reflection is precisely what the book undertakes.
Chapter II: The Nature of Concepts
Here MacIntyre moves from the broad problem of categories to a more specific analysis of concepts themselves — what they are, how they function, and how they are acquired. This chapter is a foundational piece of the work’s argument, because categories are themselves a special kind of concept, and understanding concepts in general is necessary to understand categories in particular.
MacIntyre begins by distinguishing between concepts as mental representations or abilities, and the words or terms that express them in language. He is careful not to collapse the two: a concept is not identical to a word, though words are the primary vehicles for expressing and sharing concepts. The key question is how concepts relate to the world they are about. He considers the empiricist view that concepts are derived from sense-experience, a position he traces from Locke through Hume. On this view, a concept is a kind of mental copy or abstraction from particular impressions. But MacIntyre finds this inadequate: it cannot account for the generality and systematicity of concepts, nor for concepts that appear to have no direct empirical origin (such as those of logic or mathematics).
He then turns to the rationalist alternative, associated with Descartes and Leibniz, which holds that certain concepts are innate or arise from the mind’s own structure. But MacIntyre argues that this position likewise faces difficulties, particularly in explaining how concepts change historically and how they are learned by individuals. The middle path he proposes draws on the work of later philosophers, especially Wittgenstein and the later philosophy of language. He suggests that concepts should be understood as rules for the use of words within a form of life. They are not private mental entities but public, norm-governed patterns of classification and inference. He writes: “To possess a concept is to know how to use the relevant term correctly, in judgment, in reasoning, and in action.”
What this means is that concepts have a social and practical dimension. They are learned through training and participation in communal practices, not through solitary introspection. A concept of “red,” for example, involves knowing how to identify red objects, how to relate red to other colors, and how to use the term in statements that can be evaluated as true or false. MacIntyre’s argument here is that concepts cannot be understood in isolation from the conceptual schemes in which they are embedded — and those schemes are, ultimately, tied to forms of social life. This chapter matters because it sets the stage for the subsequent analysis of categories: categories are the most general concepts, the highest-order rules that organize other concepts, and they too must be understood in terms of their use and their historical development.
Chapter III: The Aristotelian Legacy
We are now in the third chapter, where MacIntyre examines Aristotle’s doctrine of categories as the first sustained philosophical attempt to answer the problem. The goal here is not simply historical exposition but to extract what is valuable and what is problematic in Aristotle’s approach, as a way of clarifying the contemporary issues.
MacIntyre presents Aristotle’s categories as a classification of the kinds of beings that there are, and correspondingly, the kinds of predicates that can be asserted of a subject. The central category is substance (ousia), which is that which exists independently and underlies all other categories. A substance is a “this-such” — an individual thing like a man or a horse. The other nine categories (quantity, quality, relation, place, time, posture, possession, action, passion) are accidents that inhere in substances and cannot exist apart from them. For example, “Socrates is pale” attributes a quality to the substance Socrates; “Socrates is in the agora” attributes a place. MacIntyre emphasizes that for Aristotle, this is not merely a linguistic classification but a metaphysical one: the categories reflect the actual structure of reality.
However, MacIntyre identifies several difficulties in Aristotle’s scheme. First, the list of categories appears arbitrary: why exactly ten? Aristotle offers no systematic principle for generating the list; it seems to be derived from an intuitive survey of kinds of predication. Second, the relationship between substance and accident is not always clear: are qualities, for instance, fully real, or do they have a derivative reality? Third, the categories seem to assume a static view of the world, where change is merely an accident of underlying substances. MacIntyre points out that this makes it difficult to account for processes, for historical change, and for relational structures that are not merely accidental.
Despite these problems, MacIntyre argues that Aristotle’s legacy is indispensable. Aristotle correctly saw that categories are not just about language but about what there is. He also saw that categories are interconnected — they form a system, not a random list. And his distinction between substance and accident captures something important about our everyday ontology: we do, in ordinary experience, treat some things as more fundamental than the properties that attach to them. MacIntyre writes: “Aristotle’s categories are an attempt to articulate the structure of the world as it is given to us in pre-philosophical experience. The question is whether such an articulation can survive critical scrutiny.” The chapter therefore ends with the Aristotelian framework as both a resource and a target: something to be learned from, but also something that must be revised or replaced in the light of later developments in science, logic, and philosophy.
Chapter IV: Kant’s Transcendental Turn
This chapter marks a major shift in the work, as MacIntyre turns to Immanuel Kant’s revolutionary rethinking of the categories. Where Aristotle saw categories as features of reality, Kant saw them as features of the understanding — the conceptual apparatus that the mind brings to experience to make it intelligible. MacIntyre’s presentation here is careful to show both the power and the limits of Kant’s approach.
MacIntyre begins by explaining Kant’s fundamental move: the transcendental deduction of the categories. Kant argued that for experience to be possible at all — for us to have unified, coherent perceptions of objects in space and time — the mind must impose certain concepts on the sensory manifold. These concepts are the categories: unity, plurality, totality, reality, negation, limitation, substance, causality, interaction, possibility, existence, necessity. They are not derived from experience but are the a priori conditions for experience. MacIntyre emphasizes that Kant’s categories are therefore necessary and universal: they are the same for all rational beings and cannot be changed or revised through empirical discovery.
MacIntyre then discusses Kant’s table of judgments, which is the basis for his table of categories. Kant derived the twelve categories from the twelve forms of logical judgment (e.g., universal, particular, singular; affirmative, negative, infinite; categorical, hypothetical, disjunctive; etc.). The idea is that because we judge in these logical forms, the categories that structure our experience must correspond to them. MacIntyre notes that this derivation has been widely criticized as artificial and arbitrary — why these twelve forms of judgment and not others? — but he also argues that Kant’s deeper insight is important: categories are constitutive of objectivity. They are not just tools for classifying already-given objects; they make objectivity possible.
However, MacIntyre identifies a crucial problem. If categories are fixed a priori, how can we account for conceptual change in the history of science and of thought? Kant’s system seems to entail that the categories we use today are the same as those used by the ancient Greeks, and that future science will always be structured by the same fundamental concepts. Yet the history of physics, for example, shows a shift from Aristotelian substance-causality to Newtonian forces to quantum mechanics. MacIntyre presses this point: “Kant’s categories are timeless; but the categories that actually govern human thought change over time.” The chapter thus sets up a central tension in the work: between the Kantian demand for universal, necessary categories and the evident historical variability of actual conceptual schemes. MacIntyre does not resolve this tension here, but he makes clear that any satisfactory theory of categories must address it.
Chapter V: Hegel and the Historicization of Categories
LOCATE: We are now at the point where MacIntyre turns to Hegel’s response to Kant — the first major historical attempt to reconcile the Kantian framework with the fact that categories change over time.
PRESENT: MacIntyre begins by observing that Hegel took Kant’s problem and transformed it. Where Kant had asked “What are the universal and necessary categories of any possible experience?” Hegel asked a different question: “How do categories develop through history as expressions of the self-unfolding of Spirit?” For Hegel, categories are not fixed containers imposed by the mind on a passive world. They are moments in the dialectical movement of consciousness itself. MacIntyre explains that Hegel’s Phenomenology of Spirit traces this movement from the simplest category — sense-certainty — through increasingly complex forms of consciousness, each of which reveals its own inadequacy and passes into the next. The categories of sense-certainty, for example, appear immediately given and certain, but when examined they dissolve into contradictions — the “here” and “now” turn out to be abstract and indeterminate. This forces consciousness into a new category: perception, with its distinction between the thing and its properties. But perception too breaks down, leading to understanding, and so on. MacIntyre writes: “Hegel’s categories are not, like Kant’s, a static list. They are a developmental sequence in which each category is both necessary and ultimately insufficient, generating its own negation and thus the next category.” The point is that the identity of each category is defined by its place in the whole system and by its relation to what comes before and after. There is no category-in-itself; there is only category-as-moment. Furthermore, Hegel extends this logic from the individual mind to world history itself. The categories that governed Greek thought — substance, accident, form, matter — were not errors that Kant corrected. They were necessary stages in the self-consciousness of Spirit, each appropriate to its historical epoch. MacIntyre notes that for Hegel, the history of philosophy is not a graveyard of dead doctrines but the living unfolding of conceptual truth. Each system contains its own partial truth, which is both preserved and overcome (Aufhebung) in the next. This is how Hegel can simultaneously affirm that Kant’s categories are real — they do structure modern consciousness — and deny that they are final or universal. They are the categories of a particular stage of history, the stage where the subject-object split defines experience.
CLARIFY: MacIntyre presents Hegel not as a refutation of Kant but as a transformation of Kant’s core insight. Where Kant froze the categories into a timeless grid, Hegel set them in motion. The categories are still necessary — but the necessity is internal to a dialectical process, not externally imposed by a transcendental subject. This matters because it makes historical variation in conceptual schemes not a threat to philosophy but its very subject matter. Hegel’s move is the first serious attempt in Western philosophy to take the historicity of categories as primary rather than as a problem to be solved or dismissed.
Chapter VI: The Collapse of the Hegelian System
LOCATE: MacIntyre now examines why the Hegelian synthesis did not hold — how the ambitious historicization of categories collapsed under its own weight and was succeeded by very different approaches.
PRESENT: The chapter opens with a blunt observation: Hegel’s system claimed to be the completion of philosophy, the final self-consciousness of Absolute Spirit. Yet within a generation, it was widely rejected. MacIntyre identifies two main lines of attack. The first came from Ludwig Feuerbach and the Young Hegelians, who argued that Hegel had mystified real material conditions. Feuerbach’s charge is pointed: Hegel’s categories, far from being the self-movement of Spirit, are actually projections of human social and natural needs. The category of Being, for example, is not the beginning of a logical system; it is the abstract expression of the feeling that something exists rather than nothing. MacIntyre quotes Feuerbach’s famous inversion: “The true relationship is not thought determining being, but being determining thought.” The second line of attack came from Søren Kierkegaard, who argued that Hegel’s system had no place for the existing individual. Hegel’s categories are universal and necessary — they describe what any rational consciousness must think. But Kierkegaard insisted that the most important truths are subjective, not objective. The category of faith, for instance, cannot be captured by the dialectic; it is a leap, a paradox, a relation to the absolute that breaks all conceptual mediation. MacIntyre presents Kierkegaard’s objection as especially damaging because it reveals a gap between the categories of systematic philosophy and the categories of actual human existence — anxiety, decision, commitment. The Hegelian system can describe everything except the concrete moment of choice. Additionally, MacIntyre notes the devastating critique from Marx, who argued that Hegel’s categories are the ideology of a particular class and epoch. The dialectic is real, but it is the dialectic of material production, not of Spirit. Categories like property, exchange, labor are not eternal forms of consciousness; they are historically specific forms of social relation generated by capitalism. For Marx, the task was not to complete Hegel’s system but to turn it right side up — to ground categories in material history rather than in Absolute Spirit.
CLARIFY: MacIntyre uses this collapse to show that the problem of categories is not solved by Hegel’s historicization. The Hegelian system promised to explain how categories change while preserving their necessity, but it failed on two fronts: it could not account for concrete individual existence (Kierkegaard) and it could not escape the charge that its own categories were merely the expression of a particular historical situation (Marx, Feuerbach). Philosophy was left, after Hegel, without a unified theory of categories — and with a growing suspicion that any such theory might be impossible.
Chapter VII: The Logical Positivists and the Elimination of Categories
LOCATE: MacIntyre now moves to the twentieth century and the attempt by logical positivism to dissolve the problem of categories entirely — by reducing all meaningful thought to the logic of science.
PRESENT: The logical positivists, particularly Rudolf Carnap and the early Ludwig Wittgenstein of the *Tractatus*, rejected the very idea of categories as a philosophical illusion. For Carnap, the only genuine questions were empirical or logical. Metaphysical questions about categories — what kinds of things exist, what the fundamental structures of reality are — were dismissed as pseudo-questions, neither true nor false but simply meaningless. MacIntyre explains the positivists’ core move: they adopted the verification principle, which held that a statement is meaningful only if it can be verified by sense experience or is a tautology of logic or mathematics. Claims about categories — “substances are the basic entities,” “there are twelve categories” — fail both tests. They cannot be empirically verified and they are not logical truths. Therefore they are not genuine claims about the world but expressions of emotion, attitude, or confusion. MacIntyre quotes Carnap: “Metaphysicians are musicians without musical ability.” The positivists did not just deny specific categorical schemes; they denied that the category question made sense at all. The world is simply what science describes, and science has no need for a special philosophical discipline of categories. The categories of physics — mass, energy, force, field — are not discovered by a priori reflection; they are defined by the theories that use them. There is no higher philosophical standpoint from which to judge them. In a key passage, MacIntyre notes: “For the positivist, the question ‘What are the categories?’ is replaced by the question ‘What are the concepts of our best scientific theories?’ And this latter question is not a philosophical one but a scientific one.” The only legitimate work for philosophy, in this view, is the logical analysis of scientific language — clarifying the syntax of theories, not prescribing their content. Wittgenstein’s *Tractatus* gave this position its most elegant expression: the world is the totality of facts, not things; the limits of language are the limits of the world; what cannot be spoken of must be passed over in silence. Categories, being neither facts nor logical structures, are precisely what must be passed over.
CLARIFY: MacIntyre presents logical positivism as a radical break with the entire tradition from Aristotle through Hegel. It does not try to revise or historicize categories; it tries to eliminate the problem by declaring it meaningless. But this move, as MacIntyre will later show, is itself a philosophical position about categories — one that cannot be justified by its own criteria. The verification principle, after all, cannot itself be verified empirically or derived logically. The positivists’ elimination of categories rests on a hidden categorical commitment: that only empirical science yields genuine knowledge. This sets up the next chapter’s critique.
Chapter VIII: Wittgenstein and the Return to Ordinary Language
LOCATE: MacIntyre now turns to the later Wittgenstein, whose work in the *Philosophical Investigations* offered a radically different response to the problem of categories — one that does not eliminate them but recontextualizes them within language games and forms of life.
PRESENT: The later Wittgenstein rejected both the Kantian search for universal categories and the positivist attempt to dismiss them. Instead, he argued that categories are local, practical, and embedded in specific human activities. MacIntyre explains Wittgenstein’s key concept: language games. A language game is a complete unit of human communication and activity — giving orders, reporting an event, speculating about the future, telling a joke, praying. Each language game has its own rules, its own concepts, its own criteria for what counts as a valid move. There is no single set of categories that underlies all language games. The categories of physics (mass, force) are appropriate to the language game of scientific explanation. The categories of religion (sin, grace, redemption) are appropriate to the language game of worship. They cannot be reduced to each other, nor can they be judged from some neutral standpoint. MacIntyre quotes Wittgenstein: “Don’t say: ‘There must be something common, or they would not be called “games”’ — but look and see whether there is anything common to all.” This is a direct rejection of the Aristotelian and Kantian method of looking for essences or necessary features. Instead, Wittgenstein proposes the concept of family resemblances: categories are like the members of a family — some share eyes, others share a nose, but no single feature is common to all. This means that the question “What are the categories?” cannot be answered by producing a list. It can only be answered by describing the many different ways human beings use language and concepts in their various activities. MacIntyre emphasizes that for Wittgenstein, philosophy is not a theoretical discipline that discovers hidden structures. It is a therapeutic activity that dissolves confusion by showing how language actually works. The mistake of both Kant and the positivists was to think that there is one correct way to talk about reality. In fact, there are many — each valid within its own form of life, each irreducible to the others.
CLARIFY: Wittgenstein’s move is subtle and important for MacIntyre’s argument. It avoids the positivist elimination of categories by showing that categories are real and functional — but only within specific contexts. It also avoids the Kantian claim that there is a single, timeless set of categories that governs all rational thought. However, MacIntyre will later point out that Wittgenstein’s position has its own difficulties. If categories are entirely local to language games, how do we account for the fact that language games change over time and conflict with each other? How do we make sense of the progress of science or the critique of one form of life by another? Wittgenstein’s pluralism, MacIntyre suggests, may leave us unable to explain conceptual change or to adjudicate between competing categorical schemes.
Chapter IX: The Sociology of Knowledge and the Problem of Relativism
LOCATE — MacIntyre turns from the purely philosophical analysis of concepts and categories to the sociology of knowledge, examining how social conditions shape categorical schemes and whether this leads to an inescapable relativism.
PRESENT — MacIntyre begins this chapter by noting that the sociology of knowledge, particularly in the tradition of Karl Mannheim, has posed a serious challenge to any account of categories that claims universal validity. If all thought is socially determined, then the categories through which we understand the world are themselves products of particular historical and social conditions. Mannheim’s central claim, as MacIntyre presents it, is that “every form of thought is bound up with the social position of those who hold it” — what Mannheim calls the “existential determination of knowledge” (Seinsverbundenheit des Wissens).
MacIntyre then examines the implications of this claim for the study of categories. If Mannheim is correct, then the Aristotelian categories, the Kantian categories, and even the Wittgensteinian language games are all expressions of particular social locations. The Aristotelian categories reflect the worldview of a slave-owning Greek aristocracy; the Kantian categories reflect the rationalism of the Prussian Enlightenment; the Wittgensteinian language games reflect the linguistic practices of a particular academic culture. There is no neutral standpoint from which to judge between these competing categorical schemes.
However, MacIntyre argues that Mannheim’s own position is internally contradictory. Mannheim tried to avoid relativism by claiming that the “socially unattached intelligentsia” could achieve a synthesis of different perspectives. But MacIntyre points out that this appeal to a privileged group simply reintroduces the problem it was meant to solve: why should the intelligentsia be exempt from the social determination that applies to everyone else? Mannheim’s solution, MacIntyre writes, “merely postpones the problem: it does not solve it.”
MacIntyre then draws on the work of Karl Marx and Émile Durkheim to deepen the sociological account. For Marx, the categories of thought are part of the “superstructure” that reflects the “relations of production” — the economic base of society. The categories of bourgeois political economy, for example, treat capitalism as a natural and eternal order, when in fact it is a historically specific mode of production. For Durkheim, categories are “collective representations” that originate in the structure of social life itself. In *The Elementary Forms of Religious Life*, Durkheim argued that the category of time derives from the rhythm of social activities, that the category of space reflects the layout of the tribe’s territory, and that the category of causality arises from the experience of social forces.
MacIntyre notes that both Marx and Durkheim provide powerful explanations of how categories are socially produced, but both also face the same difficulty: if all categories are socially determined, then the categories of Marx’s own theory of history or Durkheim’s own sociological method are themselves mere reflections of their social positions. As MacIntyre puts it, “The sociology of knowledge threatens to consume its own foundations.”
CLARIFY — MacIntyre is not rejecting the sociology of knowledge; he is showing that it raises a problem that must be addressed rather than evaded. The sociological account of categories is compelling because it explains why different societies have different categorical schemes. But if taken to its extreme, it becomes self-refuting — it cannot account for its own status as knowledge. This sets up the need for a more nuanced account that can acknowledge the social origins of categories while still preserving the possibility of rational critique and truth.
Chapter X: Categories and Conceptual Change
LOCATE — MacIntyre now moves to the central problem of how categories change over time, examining the work of Thomas Kuhn and other philosophers of science who have grappled with the dynamics of conceptual revolution.
PRESENT — MacIntyre opens this chapter by stating that any adequate theory of categories must account for conceptual change — the fact that categorical schemes are not static but evolve, sometimes gradually and sometimes through radical transformation. He takes as his starting point Thomas Kuhn’s *The Structure of Scientific Revolutions*, which argues that science does not progress through the simple accumulation of facts but through periodic “paradigm shifts” that transform the very categories within which scientists think.
Kuhn’s central concept, as MacIntyre presents it, is that of a paradigm — a set of assumptions, methods, and categories that defines what counts as a legitimate problem and a valid solution within a scientific community. Normal science operates within a paradigm, solving puzzles that the paradigm defines as relevant. But anomalies accumulate, and eventually a crisis leads to a revolution in which the old paradigm is replaced by a new one. Crucially, Kuhn argues that paradigms are “incommensurable” — there is no neutral set of categories by which they can be compared. The categories of Aristotelian physics (such as “natural motion” and “violent motion”) cannot be directly translated into the categories of Newtonian physics (such as “inertia” and “force”).
MacIntyre examines the concept of incommensurability in detail. If categories are truly incommensurable, then the history of science is not a story of progress toward truth but a series of discontinuous shifts between different conceptual worlds. A scientist working within one paradigm cannot even fully understand the claims of a scientist working within another, because the terms have different meanings. As MacIntyre puts it, quoting Kuhn, “Though the world does not change with a change of paradigm, the scientist afterward works in a different world.”
MacIntyre then raises a critical question: if paradigms are incommensurable, how do scientists ever choose between them? Kuhn’s own answer is that the choice is based on “values” such as accuracy, consistency, simplicity, and fruitfulness — but these values are themselves interpreted differently within different paradigms. MacIntyre notes that this seems to reduce scientific change to a kind of conversion experience, more like religious conversion than rational deliberation.
To address this, MacIntyre turns to the work of Imre Lakatos and his concept of “research programmes.” Lakatos argued that scientific theories are not isolated but form sequences of theories connected by a “hard core” of assumptions and a “protective belt” of auxiliary hypotheses. Scientific change can be rationally evaluated by comparing the “progressive” or “degenerating” character of research programmes — whether they predict new facts or merely protect themselves from refutation. MacIntyre finds Lakatos’s account more satisfactory than Kuhn’s because it allows for rational comparison between competing programmes over time, rather than treating them as completely incommensurable.
CLARIFY — MacIntyre is working toward a middle ground: he accepts that categories are historically conditioned and can undergo radical change, but he rejects the conclusion that such change is purely irrational. The task, as he sees it, is to develop an account of rational change that does not presuppose a fixed, timeless set of categories but also does not collapse into relativism. The concepts of paradigm shifts and research programmes provide tools for thinking about this, but MacIntyre will need to integrate them with the broader history of philosophy he has been tracing.
Chapter XI: Tradition and Rationality
LOCATE — MacIntyre now develops his own positive account of how rational inquiry proceeds within traditions, drawing on insights from Aristotle, Aquinas, and later thinkers to construct a model of tradition-constituted rationality.
PRESENT — MacIntyre begins this chapter by arguing that the notion of rationality as a set of universal, context-free rules — what he calls “the Enlightenment project” — has failed. The Enlightenment hoped to establish a standard of rationality that all reasonable people could accept, regardless of their cultural or historical location. But this project, MacIntyre argues, has been unable to resolve fundamental disagreements, and the attempt to find a neutral standpoint has led either to empty formalism or to the kind of relativism examined in the previous chapters.
Instead, MacIntyre proposes that rationality is always embodied in traditions — historically extended, socially embodied arguments about the goods that constitute a form of life. A tradition, in his sense, is not a static inheritance but a living debate: “A tradition is an argument extended through time in which certain fundamental agreements are defined and redefined in terms of both internal and external conflicts.” The categories of a tradition are not fixed once and for all; they are developed, criticized, and transformed through ongoing inquiry.
MacIntyre then traces how this model of tradition-constituted rationality works in practice. He takes the example of the Aristotelian-Thomistic tradition, which he has already discussed in earlier chapters. Aristotle developed a set of categories based on his metaphysical and biological investigations. These categories were later criticized and modified by Aquinas, who integrated them with Christian theology and with insights from Islamic philosophy. The tradition continued to develop through later Scholastic thinkers, through the Counter-Reformation, and into the twentieth-century revival of Thomism. At each stage, the tradition’s categories were not simply repeated but refined in response to challenges.
The key point, MacIntyre emphasizes, is that traditions can be rationally evaluated — but only from within a tradition or from the perspective of another tradition. There is no neutral, tradition-independent standpoint. However, this does not lead to relativism, because traditions can recognize their own inadequacies and can learn from other traditions. A tradition that encounters problems it cannot solve internally — what MacIntyre calls an “epistemological crisis” — may be able to overcome that crisis by borrowing from or engaging with another tradition. The superiority of one tradition over another is shown by its ability to explain the failures and limitations of its rival while also accounting for its own history.
MacIntyre illustrates this with the example of the encounter between Aristotelian physics and Galilean physics. The Aristotelian tradition faced an epistemological crisis because it could not account for the motion of projectiles or the behavior of falling bodies in the terms available to it. Galileo’s new physics, drawing on Archimedes and on the tradition of mathematical description, was able to explain both the phenomena that Aristotle’s physics could explain and the anomalies that it could not. Moreover, Galileo could explain why Aristotelian physics had seemed plausible for so long — because its categories were well-suited to ordinary experience under everyday conditions. This ability to account for the history of the rival tradition, MacIntyre argues, is the mark of rational superiority.
CLARIFY — MacIntyre’s account of tradition-constituted rationality is his answer to the problems raised throughout the book. Categories are not timeless and universal, as Kant thought; they are historically developed and socially embodied. But they are not merely arbitrary or incommensurable, as some readings of Kuhn and Wittgenstein suggest. Rationality consists in the ability of a tradition to identify and resolve its own problems, to engage with rival traditions, and to provide a better account of both its own history and the history of its competitors. This is a model of rationality that is neither foundationalist nor relativistic.
Chapter XII: The Rationality of Traditions
LOCATE — We are in the penultimate chapter of the work, where MacIntyre moves from the historical survey of theories of categories to a constructive philosophical argument about how traditions, the bearers of categories, can be genuinely rational.
PRESENT — MacIntyre begins by rejecting two dominant modern pictures of rationality. The first is the Enlightenment picture, which holds that rationality consists in the adherence to standards that are universal, timeless, and independent of any particular tradition or culture. The second is the relativist picture, which holds that each tradition has its own standards and there is no way to adjudicate between them. Both are mistaken because they share a false premise: that rationality must be tradition-independent. MacIntyre’s central thesis is that “rationality is tradition-constituted.” This does not mean that traditions are closed systems or that reason is merely a tool of tradition. Rather, it means that all reasoning takes place within some set of inherited categories and standards, and that the rationality of a tradition is demonstrated by its ability to overcome its own limitations and engage with rivals.
The key concept is that traditions have epistemic crises. When a tradition encounters problems it cannot solve using its own resources — problems that reveal internal inconsistencies, explanatory failures, or anomalies — the tradition is faced with a choice: it can stagnate and die, or it can transform itself. The transformation is rational if it can overcome the crisis by providing a better account of the tradition’s own history and its problems than the tradition could previously provide. MacIntyre uses the example of the transition from Ptolemaic to Copernican astronomy. The Ptolemaic tradition faced an accumulating set of anomalies — the planets did not move as the theory predicted, and the epicycles became increasingly complex and ad hoc. The Copernican revolution was rational because it could explain why the Ptolemaic tradition had the problems it did and could solve them in a way that preserved many of the achievements of the earlier tradition.
“A tradition is an argument extended through time in which certain fundamental agreements are defined and redefined in terms of two kinds of conflict: those with critics and enemies external to the tradition who reject all or at least key parts of its fundamental agreements, and those internal, interpretative debates through which the meaning and rationale of the fundamental agreements come to be expressed.”
MacIntyre argues that the rationality of a tradition is demonstrated in three stages. In the first stage, the tradition is in a state of undisturbed development, where its categories and standards are taken for granted and it is able to solve the problems it sets for itself. In the second stage, the tradition encounters epistemic crises that it cannot resolve. Anomalies accumulate, problems become intractable, and the tradition’s own adherents begin to lose confidence. In the third stage, the tradition is confronted by a rival tradition that can provide a better explanation of the crisis. The rational response is for the adherents of the troubled tradition to acknowledge the superiority of the rival and to convert to it. This conversion is not a matter of mere persuasion or power; it is a rational judgment based on the rival’s explanatory power and ability to make sense of the history of the tradition it replaces.
CLARIFY — MacIntyre’s account of tradition-constituted rationality is designed to avoid both the Enlightenment’s illusion of tradition-free reason and the relativist’s denial of any rational standards. Traditions are not prisons; they are dynamic, self-correcting communities of inquiry. The rationality of a tradition is shown in its ability to identify and overcome its own crises, and in its capacity to engage with rival traditions in ways that produce genuine learning. This is a model of rationality that requires historical understanding, intellectual humility, and a willingness to be transformed.
Chapter XIII: Categories and the Unity of the Self
LOCATE — In the final chapter, MacIntyre turns from the historical and social dimensions of categories to their role in the constitution of the self and the unity of a human life.
PRESENT — MacIntyre argues that categories are not just conceptual schemes for organizing experience; they are also the frameworks within which individuals understand themselves and their lives. The unity of the self is not a given; it is an achievement that depends on the categories a person uses to narrate and interpret their existence. Human beings are story-telling animals, and their lives are constituted by the narratives they tell about themselves. These narratives are structured by categories of causality, agency, responsibility, identity, and time. When these categories break down, the self fragments. MacIntyre offers the example of someone who undergoes a radical conversion — a religious conversion or a political conversion — and finds that the categories that once organized their life no longer make sense. The old self is dead, and a new self is born. But this new self is still connected to the old self through the narrative of transformation. The unity of the self is the unity of a narrative, not the unity of a substance.
The key concept is that of a narrative unity. MacIntyre argues that a human life is intelligible only insofar as it is understood as a narrative with a beginning, middle, and end. This narrative is not something we simply invent; it is shaped by the traditions and communities we belong to. The categories we inherit from our tradition provide the basic plot structures, character types, and moral frameworks that make our lives meaningful. When a tradition is healthy, its categories enable individuals to live coherent, meaningful lives. When a tradition is in crisis, its categories fail to provide this coherence, and individuals experience anomie, rootlessness, and a loss of identity.
“The unity of a human life is the unity of a narrative quest. Quests sometimes fail, are frustrated, abandoned, or dissipate into confusion. But the only criteria for success or failure in a human life as a whole are the criteria for success or failure in a narrated quest.”
MacIntyre argues that the modern self, especially in liberal, individualist societies, is characterized by a fragmentation of categories. Without a shared tradition to provide a coherent narrative structure, individuals are left to construct their own identities from whatever cultural fragments are available. This leads to the condition of the modern self as a “bundle of desires” or a “role-player” with no core identity. MacIntyre contrasts this with the Aristotelian-Thomistic tradition, in which the self is understood in terms of its telos — its ultimate purpose or end. The categories of that tradition — virtue, habit, friendship, community, God — provide a rich framework for understanding the self as a narrative quest toward the good.
CLARIFY — MacIntyre’s argument in this chapter brings together the themes of the entire work. Categories are not just theoretical concepts; they are the very fabric of human life and identity. The crisis of categories in modern philosophy is also a crisis of the self. The fragmentation of categories — the loss of a shared framework for understanding the world, the self, and the good — is a central problem of modernity. MacIntyre’s solution is not to return to a pre-modern tradition wholesale, but to recover the resources of the Aristotelian-Thomistic tradition for understanding the self as a narrative unity engaged in a quest for the good life, a quest that is rational and social, not merely individual and subjective.
Conclusion: The Tasks Ahead
LOCATE — MacIntyre offers a brief concluding reflection that looks forward to the philosophical work that remains to be done, both in the study of categories and in the project of reviving a tradition-constituted rationality.
PRESENT — MacIntyre does not claim to have provided a complete theory of categories or a fully developed account of tradition-constituted rationality. He has, he says, offered a series of prolegomena — preparatory studies — that clear the ground for a more adequate treatment. The historical survey has shown that the concept of categories is indispensable to philosophy, but that every previous attempt to provide a definitive list or a transcendental deduction has failed. The epistemological and sociological investigations have shown that categories are historically dynamic and socially embodied, but that this does not entail relativism. The constructive arguments have shown that traditions can be rational and that the self is constituted by narrative categories.
The central task that remains, MacIntyre suggests, is to develop a philosophical anthropology that can do justice to both the historical contingency of categories and the possibility of rational progress. This would require a detailed working out of the categories of the Aristotelian-Thomistic tradition, showing how they can be applied to contemporary problems and how they can engage in rational debate with rival traditions — especially the liberal individualism that dominates modern culture. It would also require a more detailed account of how traditions develop, how they resolve epistemic crises, and how conversions between traditions can be rational.
“The work of recovering a tradition is never finished. It is a task that must be undertaken anew by each generation, in the face of new challenges and new crises. The only guarantee of its value is the quality of the life it makes possible.”
MacIntyre ends with a call to philosophical work that is both historical and constructive. The study of categories is not a mere antiquarian exercise; it is essential to understanding who we are and how we can live well. The crisis of categories in modern philosophy is also a crisis of modern culture, and the recovery of a tradition-constituted rationality is not just an academic project but a practical one, aimed at the reshaping of human life in accordance with the good.
