Triết học hiện đại
Human reason is the most reliable source of knowledge.
Attempts to provide rational foundation for the new science of Galileo and Newton
Emphasis on metaphysics, mathematics, and deductive reasoning: human reason seeing through appearances to underlying reality · Rationalist positions on the mind-body problem:
Dualism (Descartes): Mind and body are two distinct substances Materialism (Hobbes): Only matter is real Parallelism (Leibniz): Mind and body are separate but move in pre-established harmony like two stopwatches started at the same instant · René Descartes (1596–1650): Meditations on First Philosophy
Methodological doubt: Systematically doubts testimony of senses, reason § Influential foundation of skepticism in epistemology
Only certainty is “I think, therefore I am”; it would be impossible to think if one didn’t exist, so thought implies existence Sum res cogitans (“I am a thinking thing”): we are essentially minds, not bodies
Distinguishes three kinds of substance: § Matter: primary attribute is extension in space § Spirit (or Mind): primary attribute is thought § God: “infinite substance” whose primary attribute is existence ·
Baruch Spinoza (1632–1677): Strict rationalist; argued that there is only one substance (monism) and that it is both God and the universe(pantheism) ·
Gottfried Wilhelm Leibniz (1646–1716)
Pioneer in math and logic: invents calculus (as does Newton)
Possible worlds: A fact is necessary if it is true in all possible worlds,contingent if it is false in some possible worlds, and impossible if it is false in all possible worlds § “Principle of the best”: Ours is the “best of all possible worlds”; ridiculed by Voltaire’s Candide through the figure of Pangloss Reality is made up of monads, simple, non-extended, unchanging substances that are the building blocks of the universe
Empiricism · All knowledge comes from experience
Rejects the rationalists’ emphasis on metaphysical speculation and innate knowledge
Emphasis on epistemology, scientific experimentation, and observation · John Locke (1632–1704): Essay Concerning Human Understanding
Tabula rasa: The mind is a blank slate at birth; all understanding comes from experience and reflection upon that experience.
Role of philosopher is as “underlabourer” to natural sciences; clear up language to secure a solid foundation for science · George Berkeley (1685–1753)
Idealism: Things have no material existence, but exist only as ideas, which minds perceive and experience (esse est percipi: “being is being perceived”) Things exist independent of individual perception only because God perceives everything · David Hume (1711–1776): Treatise of Human Nature
Hume’s fork: All knowledge is either a relation of ideas (independent of experience, e.g., math) or a matter of fact (based on experience, e.g., science). Causality and uniformity in nature are not rationally justified ; they are simply the result of custom and habit.
Enlightenment is an 18th-century movement that seeks to better society through the use of reason and philosophy · Philosophes: 18th-century French philosophers such as Denis Diderot, Voltaire, Baron de Montesquieu
Reason combats ignorance and betters the human condition. · Deism: Belief that God created a universe governed by set principles that can be discerned with science and reason (Voltaire) God is a “blind watchmaker”: no divine intervention
Immanuel Kant (1724-1804) · Metaphysics/epistemology: Critique of Pure Reason
Transcendental idealism synthesizes rationalism and empiricism Distinguishes between: § Analytic propositions: Predicate concept is contained in subject concept (e.g., all unmarried men are bachelors) § Synthetic propositions: Predicate concept is not contained in subject concept (e.g., all swans are white)
And between: § A priori knowledge: Knowledge from reason § A posteriori knowledge: Knowledge from experience Space, time, and causality are synthetic a priori concepts of the understanding: reality is shaped by the perceiving mind
Human knowledge is limited to phenomena (reality as presented to the mind) Noumena or things-in-themselves exist, but are unknowable § Metaphysics must be limited to a critique of human reason · Ethics: Grounding for the Metaphysics of Morals Ethics based in human autonomy: capacity for rational deliberation
Categorical imperative: Act only in such a way that you could want the motivating principle of your action to become a universal law.
German Idealism (and Its Critics) ·
Influenced by Kant but rejects his view of the unknowable noumenal world;the only real world is the rational world, which is knowablen · Important early idealists include Fichte and Schelling · G. W. F. Hegel (1770–1831)
All of reality is part of an interconnected system that undergoes a logical historical development § The Absolute Idea is the final expression of the system.
The system functions through the dialectic: the development of ideas through a back-and-forth interaction with opposing ideas § Thesis (an initial argument) and antithesis (the opposite argument) combine to form a synthesis
Hegel’s theory of history § Based on the idea of the dialectical development of spirit in history § The Absolute Spirit is the final end of this process; mirrors Absolute Idea § Zeitgeist: The spirit of a particular age · Arthur Schopenhauer (1788–1860): Fierce opponent of Hegelian idealism
Divides the world into will (things-in-themselves) and representation(phenomena) · Other critics of Hegel include Marx And Kierkegaard
Marxism · Karl Marx (1818–1883)
Rejects an individualistic state of nature; human life is necessarily social § Human nature is an expression of labor, or human activity, performed for the benefit of society § Alienation: Workers forced to sell their labor for a wage are detached from their labor, and hence from their human nature
Dialectical Materialism: Marx’s theory of history
Expresses Hegel’s historicism in material rather than spiritual terms § History is embodied in changing relationships of production (economics) § Dialectic of class struggle moves through feudalism and capitalism towardcommunism: workers collectively own the means of production
Ideology: Ideas that express the interest of a particular social class, such as the bourgeoisie · 20th-century Marxism
Social rights: Rights based on humans’ nature as social beings. Includes rights to food and shelter Antonio Gramsci (1891–1937): Discusses hegemony, the power of the ruling class to create consent for its position through the use of social and cultural forces.
Frankfurt School (founded 1923): Includes Max Horkheimer, Theodor W. Adorno, Herbert Marcuse, Walter Benjamin, and Jürgen Habermas § Critical theory: Aims to change society by understanding ideas as products of social processes; rejects determinism
Existentialism stems from the belief that ethics and meaning must come from an individual experience of the world. · Søren Kierkegaard (1813–1855)
Rejects Hegelian system; focuses on truth as subjective meaning Three “stages on life’s way”: § Aesthetic: individualistic emphasis on physical sensations § Ethical: selfless emphasis on public good § Religious: individual’s personal relationship with God
Anxiety (angst): the fear one feels in face of one’s own freedom Leap of faith: Religion cannot be understood rationally, but requires a personal choice to believe in God · Friedrich Nietzsche (1844–1900)
Opposes nihilism, a belief in nothing § ”God is dead”: Christian faith is no longer a generally accepted basis for morality; with the rise of atheism, Western culture is decentered and has no positive values Will to power: The fundamental drive motivating all things in the universe § Represents an “instinct for freedom” or drive for autonomy from and dominance over all other wills
Perspectivism: There is no absolute truth, merely different perspectives Superman (or “overman”): someone who has so refined his will to power that he has freed himself from all outside influences and created his own values (described in Thus Spoke Zarathustra) · Phenomenology: A theory of knowledge focused on the examination of an individual’s mental processes
Intentionality: The act of thinking involves thinking about something. “The direction of the mind on an object.” (Franz Brentano, 1838–1917)
Bracketing: Setting aside assumptions and theoretical speculations about the world; allows objective investigation of mental functions and intentionality.
Edmund Husserl (1859–1938): Consciousness, free from assumptions, is the essence of experience. · Martin Heidegger (1889–1976): Focuses on the problem of actually “being” (in German, dasein) rather than reflecting on consciousness ·
Jean-Paul Sartre (1905–1980): Being and Nothingness: “Existence precedes essence”; there is no essential “human nature.” We define who we are by the choices we make.
Simone de Beauvoir (1908–1986): The Second Sex: Patriarchal society objectifies women, inhibiting subjective experience
Transcendentalism: Emphasizes democratic spirituality, intuitive knowledge, and direct connection between people, God, and nature
Ralph Waldo Emerson (1803–1882): Emphasizes self-reliance and personal freedom.
Henry David Thoreau (1817–1862): Rejects dehumanizing materialism in favor of spiritual communion with nature ·
Pragmatism: Knowledge is a guide for action, not a search for abstract truth.
C. S. Peirce (1839–1914): The meaning of an idea consists of the consequences to which it would lead William James (1842–1910): To fully understand something we must understand all of its consequences; true beliefs will lead to positive consequences
Applies advances in math and logic to clarifying philosophical method
“Linguistic turn” in philosophy: solves philosophical problems by analyzing the language in which they’re expressed.
Hostile to metaphysics: meaningful questions should be settled through logic and scientific investigation alone · Gottlob Frege (1848–1925)
Develops quantifier logic, first major advance in logic since Aristotle
Uses logic to analyze meaning: § Sense: What a person knows when they understand a word § Reference: Object to which the word refers·
Bertrand Russell (1872–1970)
Logicism: Attempts to reconstruct math from logical axioms ( Principia Mathematica, written with A. N. Whitehead)
Russell’s Paradox: Does a class exist that consists of all classes that are not members of themselves? § There is no noncontradictory answer to this question: serious problem for logic
Grammar masks meaning: logical analysis of sentences brings out underlying logical form Logical empricism: All knowledge is built from unanalyzable sense data.
Ludwig Wittgenstein (1889–1951): Philosophical problems dissolve when we understand the language in which they’re expressed.
Tractatus Logico-Philosophicus (1921): Only scientific propositions have meaning; propositions about ethics, metaphysics, etc. are meaningless.
Philosophical Investigations (1953): Ordinary language philosophy:Meanings of words lie in their everyday use. ·
Logical positivism (the Vienna Circle: Schlick, Carnap, Neurath) Verification principle: The meaning of a sentence is its means of verification; unverifiable sentences (e.g., metaphysics) are meaningless ·
Kurt Gödel (1906–1978): Incompleteness Theorem: All logical systems necessarily contain statements that cannot be proved within the system itself · W. V. O. Quine (1908–2000): Naturalized epistemology Criticizes analytic/synthetic distinction: Any statement in a system can be true, given enough adjustment of other statements in the system
Ferdinand de Saussure (1857–1913): Semiology: Language is a structured system of signs
Distinguishes between: § Signified: The thing to which a word refers § Signifier: The word that does the referring. The relationship between signifier and signified is arbitrary: words only have meaning in relation to other words.
Similarly separates: § Langue: The general system and rules of language § Parole: Concrete utterances whose meaning comes only from their relationship to other words in the system · Other structuralists apply semiology to anthropology (Lévi-Strauss), psychology (Lacan), and myth (Barthes) ·
Meaning is fluid; there is no absolute truth.
Michel Foucault (1926–1984): What is accepted as knowledge reflects not reality but the structures of power present in a particular historical period.
Jacques Derrida (1930–2004): Deconstruction: Method of taking apart, or invalidating, the presumed meaning of a text · Feminist epistemology: The human experience is more than just the male experience. Subjectivity: Emphasizes the validity of the views or feelings of a particular subject Scientific and philosophical “objectivity” can be seen as forms of malesubjectivity.