Philosophy Glossary

Truth — The property of what conforms to reality or to what is asserted; one of philosophy’s central concepts, whose nature is disputed by several rival theories. The Latin veritas renders the Greek alḗtheia, literally “non-concealment” or “unveiling.” The oldest and most influential theory is that of correspondence: a proposition is true if it agrees with the facts. Aristotle formulates it in the Metaphysics — to say of what is that it is, and of what is not that it is not, is true; the Scholastic tradition crystallizes it in the formula adaequatio rei et intellectus (the adequation of thing and intellect). In the twentieth century, Alfred Tarski gave it logical rigor with his semantic theory, on which “‘snow is white’ is true if and only if snow is white.” Competing conceptions include the coherence theory, championed by British idealism, for which truth is the consistency of a proposition with an integrated system of beliefs; the pragmatic theory, which takes distinct forms: for Charles Peirce, a belief is true if it is the opinion to which all investigators would ultimately converge at the end of indefinitely prolonged inquiry (the “ideal limit of inquiry”); for William James, the true is what proves useful and works in practice, bearing fruit in conduct; and deflationary theories, for which saying “p is true” adds nothing to simply asserting p, so that truth is no substantive property. Martin Heidegger, for his part, recovers the Greek sense and holds that originary truth is alḗtheia — the unconcealment of being, prior to truth understood as the mere agreement of statement and thing. Closely related concepts are those of proposition and fact. ...

Universals — That which can be predicated of many individuals or be present in many particulars at once, as opposed to the particular, which is single and unrepeatable. Terms such as “human,” “white,” or “triangle” seem to name something common to countless distinct things: what makes Socrates and Plato equally human? The central question, known as the problem of universals, asks whether such general terms correspond to any real entity or are merely words. The classic formulation reached the Latin Middle Ages through Porphyry’s Isagoge, commented upon by Boethius, which asked whether genera and species exist in reality or only in the understanding. Three major positions structure the debate. Realism holds that universals have an existence of their own: for Plato they are the Forms or Ideas subsisting apart from sensible things, a line inherited by the Augustinian tradition and by Anselm of Canterbury. Nominalism denies such existence and reduces universals to names (nomina) or linguistic signs we apply to similar things, a view associated with William of Ockham and his principle of economy. Between the extremes, the conceptualism of Peter Abelard maintains that universals are neither things nor mere words, but concepts formed by the mind from what particulars share in common. The theme runs through ancient and medieval metaphysics and remains alive in contemporary analytic philosophy, tied to questions about properties, natural kinds, and the status of abstract entities. ...

Utilitarianism — An ethical doctrine holding that the morally correct action is the one that produces the greatest amount of happiness for the greatest number of people. Its core is the principle of utility (or “greatest happiness principle”): a course of conduct is good insofar as it increases the pleasure and reduces the suffering of those affected by it, counting each person’s well-being impartially. The term derives from the Latin utilitas (“usefulness”, “benefit”). The classic formulation comes from Jeremy Bentham, in An Introduction to the Principles of Morals and Legislation (1789), who proposed a “felicific calculus” to measure pleasures and pains according to criteria such as intensity, duration, and extent, treating all pleasures as qualitatively equal. John Stuart Mill, in Utilitarianism (1863), refined the theory by distinguishing “higher” pleasures (intellectual and moral) from “lower” pleasures (merely sensory), arguing that the former are of greater worth. Utilitarianism is a form of consequentialism: what makes an act right or wrong is solely its consequences, not the agent’s intentions nor adherence to rules considered in themselves. For this reason it often clashes with deontological ethics, such as Kant’s, which judge an action by duty rather than by results. A central distinction sets act utilitarianism — which evaluates each individual action — against rule utilitarianism, which approves an action according to rules whose general adoption maximizes utility. It is also tied to hedonism, since it identifies the ultimate good with pleasure or happiness. ...

Virtue (Areté / Virtus) — A stable excellence of character that disposes a person to act well consistently. The Greek term areté originally denotes the excellence proper to anything in fulfilling its function: the areté of a horse is to run well, that of a human being is to live according to reason. In the Nicomachean Ethics, Aristotle distinguishes the intellectual virtues, acquired through teaching (such as sophia and phronesis, or practical wisdom), from the moral virtues of character, acquired by repeating good actions until they become a habit (hexis). Moral virtue lies as a mean (mesotes) between two vices, one of excess and one of deficiency: courage is the mean between recklessness and cowardice; generosity, between prodigality and stinginess. This mean is not mathematical but relative to each situation, and it falls to practical wisdom to discern it. The ultimate end of the virtues is eudaimonia, the good and flourishing life. Before Aristotle, Plato (Republic IV) had articulated the four cardinal virtues — prudence, justice, fortitude, and temperance — later absorbed by the Stoic and Christian traditions, the latter adding the theological virtues (faith, hope, charity). After centuries dominated by ethics of duty (deontology) and of consequences (utilitarianism), virtue ethics was revived in the 20th century, above all by Alasdair MacIntyre in After Virtue (1981), who placed character and community back at the centre of moral reflection. ...

Weltanschauung — German for “worldview” or “vision of the world”: the articulated set of presuppositions, values, and beliefs that structures how an individual, a culture, or an era understands reality as a whole. The term combines Welt (“world”) and Anschauung (“intuition,” “view,” “way of seeing”); it first appears in Kant’s Critique of the Power of Judgment (1790) in a sense still tied to the sensory apprehension of the world, and only later becomes a philosophical concept in its own right. It was above all Wilhelm Dilthey who turned it into a centerpiece of his thought: in his Weltanschauungslehre (doctrine of worldviews), a worldview is not a mere theory but a living totality that encompasses one’s grasp of reality, one’s evaluation of values, and the orientation of the will. Dilthey distinguished three recurrent types of metaphysical worldview: naturalism (Democritus, Hobbes), the idealism of freedom (Plato, Kant), and objective idealism (Heraclitus, Spinoza, Leibniz, Hegel). The notion later became central to philosophical anthropology and the sociology of knowledge. Heidegger, however, problematizes the concept: every “worldview” presupposes that the subject stands before the world as before an object to be represented — a stance he regards as typical and symptomatic of Modernity, the age in which “the world is conceived as picture.” The term is close to notions such as cosmovision and paradigm, but differs from them in designating an existential and evaluative synthesis rather than a merely theoretical scheme. ...

Will (Boúlesis / Voluntas / Wille) — The faculty of deliberation, willing, and choice by which an agent determines itself to act. The Latin voluntas, tied to the verb velle (to will), renders the Greek boúlesis, the rational desire already analyzed by Aristotle. Although antiquity discussed choice (proaíresis) and desire, it was Augustine who placed the will at the center of moral and spiritual life: sin springs not from ignorance but from a will that turns away from God toward created goods—a will that can be divided against itself, as he describes in the Confessions. In modern thought, Kant distinguishes Wille (the legislative will, identical with pure practical reason, which gives itself the moral law) from Willkür (the power of choice, the capacity to adopt maxims and to choose between duty and inclination); this distinction underpins his doctrine of autonomy. Schopenhauer breaks with intellectualism: in The World as Will and Representation, the Will (Wille zum Leben, “will to live”) is the blind, single, irrational essence of all reality, prior to representation, from which the subject can free itself only through aesthetic contemplation or asceticism. Nietzsche reinterprets this drive as the Will to Power (Wille zur Macht): a creative, self-affirming force that exceeds mere self-preservation. The notion connects directly to the problem of free will and to the distinction between will and desire (undeliberated sensory appetite). ...

Wille zur Macht — German expression usually rendered as will to power, a central concept of Friedrich Nietzsche’s philosophy. For Nietzsche the will to power does not primarily mean the human desire to dominate others, but a more fundamental tendency: the drive of every living force to expand, to overcome resistance, to grow and to impose form on its surroundings. It is less a conscious wanting than the basic dynamic running through all organic life and, in some formulations, through the whole of reality. The concept comes to the fore in Thus Spoke Zarathustra (1883–1885) and in Beyond Good and Evil (1886), where Nietzsche sets his thesis against Schopenhauer’s will to live (Wille zum Leben): living beings, he argues, do not merely seek to preserve themselves but above all to discharge and enlarge their strength. A recurring example is his reading of morality itself: values such as humility and compassion would be, on Nietzsche’s account, indirect ways in which the weak exercise their will to power. The title The Will to Power (Der Wille zur Macht) also designates a posthumous compilation of notebook fragments, assembled from 1901 under the direction of his sister Elisabeth Förster-Nietzsche and Peter Gast; later philological scholarship, above all the Colli–Montinari edition, showed that this arrangement does not correspond to a work Nietzsche himself planned. The concept is closely bound up with the eternal recurrence and with the figure of the overman (Übermensch). ...

Zoe / Bios (ζωή / βίος) — A Greek distinction between two senses of “life.” Zoe names bare life, the simple fact of being alive shared by all living things — humans, animals, and gods — that is, biological life in its most elementary sense. Bios, by contrast, denotes qualified life, life endowed with form and a proper way of existing: the particular manner of living of an individual or group, such as the life of the citizen, the philosopher, or the politician. The distinction is central to Aristotle, for whom the human being is zoon politikon (a political animal): unlike mere living (zen), the human end is “living well” (eu zen), which is fully realized only in the polis, in a community governed by speech and law. Thus the bios politikos — the active life of the city — is set apart from the bios theoretikos, the contemplative life devoted to knowledge. In the twentieth century, Giorgio Agamben revives this opposition in Homo Sacer: Sovereign Power and Bare Life (1995) to analyze modern biopolitics. For Agamben, Western politics has from the outset been founded on the inclusion of zoe within the sphere of sovereign power: the Roman figure of the homo sacer — one who may be killed without the act counting as homicide or sacrifice — embodies this “bare life” captured by law. The concept engages directly with Michel Foucault’s biopolitics and with the notion of the state of exception, in which the border between zoe and bios becomes indistinct. ...