Philosopher(s)

Period

Ideas/Contributions

Milesians (Thales, Anaximander, Heraclitus, Anaxagoras)

7th Century B.C.

Asked what universe is made of (Thales: water; Heraclitus: fire). Heraclitus: "Strife is the father of all." Anaxagoras: "There is a portion of everything in everything" -- earliest theory of infinite divisibility. Each helped to shape the beginning of the scientific method: i.e., by gathering facts, developing and testing an hypothesis.

Pre-Socratics (among them Empedocles, Parmenides, Zeno of Elea, Euclid, Pythagoras)

Late 7th Century B.C. To Early 5th Century B.C.

These thinkers advanced ideas about the essence of things (Empedocles: water, air, fire, and earth the basic "stuff"), about unity/plurality (Parmenides: the world is a uniform solid, spherical in shape; "Being is, Non-Being is not"; empty space cannot exist if all things are made of basic stuff), paradoxes of space and motion (Zeno), logic and mathematical theory (Euclid, Pythagoras). Plato's Theory of Forms was greatly influenced by Parmenides' notion of the One and by the mathematical conclusions of Pythagoras.

Eastern prophets, moral teachers (Lao-Tse, Confucius, the Buddha among them)

6th Century B.C.

Each influenced the history of ethics and religion in India, China, and Japan. Confucius' ethics centered on the ideas of benevolence, filial piety, and reciprocity (treating others as one would wish to be treated). The Buddha, a title meaning "the enlightened one," said life itself is marked by suffering, and that the path to transcendence (nirvana) lay in avoiding the extremes of self-indulgence and self-mortification. Lao-Tse discerned an underlying reality of all things, the understanding of which depends on emptying one's soul and focusing on "The Way," or Tao. His ideas are laid out in the Tao Te Ching. Many religious sects and sub-sects were spawned.

Socrates, Plato, Aristotle

Early 5th Century B.C. To Late 4th Century B.C.

Perhaps the three greatest philosophers ever. Socrates developed a method of questioning designed to expose weaknesses in the interrogated (sometimes referred to as the maieutic method, in which the questioner acts as a midwife, helping to give birth to others' thoughts). He believed circumspect use of language and endless self-questioning are crucial in the quest for wisdom. Teacher of Plato, world-sage in outlook, he saw philosophy as a way of life, the highest calling of a select few. For him the highest good is knowledge. He wrote nothing but dramatically influenced the course of intellectual history. Plato, teacher of Aristotle, set forth his philosophy in dialogues, chief protagonist of which was Socrates, his mentor; he founded the Academy (c. 387 BC), perhaps the first institution of learning in the western world. Most famous for his Theory of Forms (phenomenal world of matter just an imperfect reflection of an immutable, transcendental world of ideas). Plato believed that knowledge is a process of remembering; the objects of knowledge are ideal and immutable. Aristotle theorized on a vast range of subjects: biology, ethics, logic, metaphysics, politics, &c. He founded the Lyceum and tutored Alexander the Great. He's considered history's first logician and biologist. His thinking influenced numerous theologians and philosophers, including St. Augustine and Thomas Aquinas. He was a naturalist who revised Plato's theory of form and matter; for Aristotle, the form is what makes matter what it is (as the soul defines a living body). He put forth two general principles of proof: the excluded middle (everything must either have or not have a given characteristic), and the law of contradiction (nothing can both have and not have a given characteristic).

Epicurus/Epicureanism

Middle 4th Century B.C. To Early 3rd Century B.C.

Known mostly for hedonistic ethical system in which pleasure is the highest good (Epicurus: "Eat, drink, and be merry for tomorrow you will die.") Quality of pleasure more important than mere quantity. Epicureans defended an atomistic view of the world (i.e., things are made up of minute, indivisible particles that move about in a void). Epicurus believed there are infinitely many worlds (what we call "galaxies" today).

Stoics (Zeno and later Roman thinkers such as Seneca, Epictetus, and Marcus Aurelius)

Early Third Century B.C. To Third Century A.D.

Name Stoicism derived from stoa, or porch, where the movement's founder Zeno (not Zeno of Elea) taught. World governed by unshakable laws laid down by God. Everything happens for a reason, so that the goal of life should be acquiescence to divine laws, not resistance. God is immanent in all matter, creates a harmonious order. Later Roman Stoics affirmed same themes: need for harmony in one's life, for spiritual growth which ideally would exist in seclusion from the everyday hassles of society.

Skeptics (Pyrrho of Elis, Timon, Antisthenes, and later, Sextus Empiricus)

Late Fifth Century B.C. To Second Century A.D.

Avoided doctrines and dogmas and sought to criticize existing ideas. Nothing is truly knowable; doubt is the most tenable disposition of mind (Pyrrho). Important harbinger of later empiricism, of the modern scientific method, of religious agnosticism. Profoundly influenced later philosophers (Descartes, Hume, Santayana among them).

Cynics (Diogenes, Antisthenes)

Fourth Century B.C. To Sixth Century A.D. (Not a continuous school)

Name "Cynic" comes from nickname given Diogenes: the Dog. Cynical philosophy unrelated to modern acceptation of the term (view that people act self- centeredly in pursuit of narrow aims). According to the older Greek philosophy, happiness is found in virtuous action; goods in the external world (wealth, fame, pleasure, individualistic ambitions) are unnatural and harmful. Ascetic self- discipline is the only path to freedom. Cynics are inclined to agree with Skeptics that little, if anything, can be known, and that one should steer clear of dogmas and popular views of things.

Christian & Arabian Philosophy

First Century A.D. To Seventeenth Century A.D. (for various Christian philosophies)

The advent of the Church led to numerous questions about Jesus' nature, about the nature of God and the universe, the nature of the Trinity, the question about faith and reason (are they naturally opposed or naturally complementary?). Philosophical speculation spills over into theological speculation. Philosophers (e.g., Origen and Clement, Boethius, Plotinus, Augustine, Avicenna, Averroes, Maimonides, and later Aquinas) are chiefly concerned with religious questions. Greatest influence on Christianity was Platonism, with its emphasis on the superiority of the soul (spirit) against all materialistic and bodily functions, the belief in a higher, transcendent world (heaven for religious devotees), belief in Truth and Virtue and acceptance of immutable, perfect Forms (Jesus being the Form of ideal humanity). Early post-Hellenistic philosophy reached its summit in the Medieval Period, with the philosophy of Anselm and Aquinas and the poetry of Dante.

Medieval Period (Boethius, Abelard, William of Ockham, Averroes, Maimonides, Anselm, Avicenna, Aquinas, Dante, Duns Scotus, among many others)

Late Fifth Century A.D. to Middle Fifteenth Century

Advent of scholasticism: strict adherence to rationalism, inclination to pore over numerous theological questions. Ideas prevalent in this era: question of universals, with nominalists (e.g., William of Ockham) rejecting metaphysical notions of Forms altogether; idea that God is the author of moral and scientific knowledge, the primum mobile of the universe; various "proofs" of God's existence (Anselm: Ontological Argument; Aquinas: 5 Proofs, one of which being the Argument from Design); debates about existence and essence; the emergence of mysticism in some quarters (e.g., in the teaching of Meister Eckhart); belief among many philosophers and tutors that reason alone cannot save a human being, that faith in God and revelation are needed. It was in this period that Dante completed perhaps the most influential poem of all time: La Commedia, chronicling the poet's fabled journey through hell, purgatory, and heaven.

Birth of Modern Science (Bacon, Copernicus, Kepler, Galileo)

Late 15th To Late 17th Centuries

Old views of the world come under scrutiny and are revised (e.g., Ptolemaic view that earth is the center of the universe). Copernicus, a Polish astronomer, challenged the Ptolemaic view; he said the sun was the center of our solar system, and that the earth and other planets revolve around it. Kepler sought to provide mathematic proofs of Copernicus' views. Galileo, an Italian physicist, combined math and science to fashion a new scientific worldview. He was the first to use a telescope, the first to confirm that Copernicus' view was correct. The Church at this time looked upon scientific experimentation with hostility and agitation; Galileo was forced to utter a recantation of his views, which he did half-heartedly. Francis Bacon, considered the father of science in England, made no actual discoveries (he was a lawyer, essayist, moral philosopher and man of letters) but gave voice to the inductive method of science and, more importantly, to empiricism (pursuit of knowledge by observation and experiment, not by use of reason alone). This period marked the end of scholasticism, the growth of intellectual curiosity and freedom, and the belief, however tacit, that knowledge about the universe can be derived not from revelation, as many of the scholastics thought, but from direct investigation and observation.

Modern Philosophy (Hobbes, Descartes, Newton)

Early 17th Century To Early 18th Century

English philosopher Thomas Hobbes was influenced by both Bacon and Galileo. He set out to construct a "master science" of "nature, man, and society"; if knowledge of nature is obtainable, Hobbes reasoned, knowledge of human nature must also be in reach. He steered away from empiricism, however, and sought to formulate principles of human conduct. The natural state of all bodies, he concluded, is motion; material universe is matter in motion. Life is motion in limbs, nerves, cells, and heart; human feelings, such as desire and aversion, are motions either towards something or away from it. Hobbes is best known for his work Leviathan, which was a defense of absolute government. Life, Hobbes said famously, is "solitary, poor, nasty, brutish, and short." Descartes, known by many as the father of modern philosophy, revisited the themes of skepticism (only thing that he couldn't doubt was himself thinking, hence cogito ergo sum); he made landmark contributions to mathematics (Cartesian geometry, as seth forth in La Geometrie), to metaphysics (belief in God and the material world, acceptance of mind-body dualism), and to philosophical methodology (Discourse On Method).

Second Half Of Modern Period (Spinoza, Leibnitz)

Mid 17th Century To Early 19th Century

Cartesian thought proved immediately influential: both Spinoza and Leibniz shared the Frenchman's passion for rationcination and developed metaphysical systems of their own. Like Descartes, Spinoza and Leibnitz believed in a rational, benevolent God. Spinoza wrote the Ethics, whose style took the form of geometrical analysis; he was a determinist, denied final causes, sought to transcend the distinction between good and evil altogether, and perhaps most controversially, equated God with creation (the doctrine of pantheism, in which each material existent is a manifestation of the divine essence, is "God's body" in a sense). Spinoza's formulation was Deus Sive Natura (Latin: God or Nature). Leibnitz's chief contribution was the monadology, the study of monads, or metaphysical units that make up substance. Monads, he said, are the elements of all things, mental as well as physical; they are indivisible. No two are alike, and change in the universe occurs because of the workings of each monad. Things are only connected by God's intervention.

Second Half Of Modern Period Cont'd. (Locke, Berkeley, Hume, Rousseau, Kant, among others)

Mid 17th Century To Early 19th Century

Locke veered away from metaphysical notions and sought instead an approach encompassing the empiricism of Bacon and the scepticism of Descartes. Purpose of philosophy is to formulate and analyze concrete problems, he said, a view which is strikingly popular in universities today. Locke denied that people are born with innate knowledge; human beings are born with a tabula rasa, or empty slate, everything subsequently known coming from sensory experience. His acceptance of constitutional government (Two Treatises of Government) influenced leaders of the American Revolution. George Berkeley, a bishop, attacked Locke's view of knowledge and instead proposed an idealist system (esse est percipi: to be is to be perceived). Matter, Berkeley said, is really only a mental representation in our mind. Hume assailed Berkeley's views of knowledge and reality and argued that reason cannot give certain knowledge. There is no proof of causality, Hume contended; the sceptical vantage point is the safest to assume in all questions of truth and knowledge. Rousseau's contribution was less in the field of epistemology, more in the areas of ethics and political philosophy (Social Contract, Confessions among his chief works). He believed that people are born good but that society wields a corrupting influence on them; like Locke, he expounded upon social contract theory. The driving force behind society is the General Will, and it must be respected. The challenge is to attain freedom amidst corruption and worldliness. Rousseau's sympathies were radical; he supported the French Revolution and contributed to a body of work known as romanticism. Two main currents in European philosophy --- the rationalism of Descartes, Spinoza, Leibnitz and the empiricism of Locke, Berkeley, Hume --- were conjoined in the work of Kant, perhaps the greatest German philosopher ever (Critique of Pure Reason on a par with Spinoza's Ethics). According to Kant, the world of things-in-themselves is unknowable; the world of appearance, the phenomenal world governed by laws, is knowable. Transcendental knowledge is impossible. Kant rejected the argument of the empiricists that all knowledge is derived from sensory experience: he believed that concepts such as causality, necessity, and unity enable us to have a coherent knowledge of the world. He accepted the moral argument for God's existence and the doctrine of free will ("ought" implies "can," he reasoned). Moral actions, he thought, can only arise from a sense of duty (as opposed to, say, the outcome of actions, which may be pleasurable or beneficial to someone).

Post-Kantian Thinkers (Schopenhauer, Fichte, Hegel, Marx, among others)

19th Century

Kant's influence was immediate and long-lasting. Schopenhauer thought the driving force of reality is Will. Knowledge depends not on reason but Will; to understand reality, we need to look inward, not outward. Schopenhauer is history's most famous pessimist, believing that all human striving is vain, that suffering is rampant, and that the only respite is to live a life of renunciation, a la the Hindus or Buddhists. Hegel defined the Absolute (unity of God and Mind), popularized the dialectical approach to truth in which assertion is followed by negation, which in turn is followed by synthesis. Hegel held that the external world is mind: there is no real bridge between the knowing mind and what the mind knows. Hegel developed an influential body of political theory in which the State is the supreme manifestation of rationality and morality; this doctrine has subsequently influenced communist and fascist political orders. Hegel exercised an enormous influence on Marx, who seized upon his predecessor's notion of the dialectic (for Hegel the dialectical process is one of ideas, a constant transition of consciousness from a lower to higher state, one undergoing constant change in history; for Marx the dialectical process is material, economic, involving class conflict and revolution). Marx excoriated religion, embraced a determinist perspective, and most of all, saw class conflict and capitalist-driven economic disparity as the hallmarks of industrial society. His name is synonymous with the Communist Manifesto, but he wrote on a wide range of subjects (Capital and the Eighteenth Brumaire two of his many important works).

Humanistic Philosophy & Growth of Modern Science (Comte, J.S. Mill, Darwin, et al.)

19th Century

French philosopher Auguste Comte is credited with developing positive philosophy, or positivism, the view that metaphysics is a meaningless endeavor and that the right emphasis for philosophy should be along the lines of the scientific method: defining and solving problems, relying on observation and experimentation to guide one's inquiries. Comte's positivism was more influential than his attempt to fashion a new religion; the latter, which he called a Religion of Humanity, was secularist in scope and failed to win many converts. Comte's writing influenced John Stuart Mill, an English economist, ethicist, logician, and political theorist. Influenced by his father, James Mill, and by Jeremy Bentham, J.S. Mill defended liberty of expression (in his classic On Liberty), fought for women's rights (The Subjection of Women), and advanced qualitative utilitarianism as a moral philosophy. Darwin, another Englishman, is of course best known for The Origin of Species, a work advancing the theory of evolution and the doctrine of natural selection. Those best adapted to their environment, Darwin said, are most successful in reproduction and hence, the propagation of their kind. The species in time will be more advanced, more evolved. Biggest philosophical ramification during Darwin's day was the undermining of the "Argument from Design" (inferring existence of God from order, design, and purpose in the world; where there's order, there must be an orderer). Darwin's theory is warmly accepted by mainstream science today, though there are numerous schools of thought on evolution.

Nihilism & Existentialism (Kierkegaard, Nietzsche, Heidegger, Sartre, among others; ideas also embodied in literary work, e.g., Dostoevsky, Kafka, Hesse)

19th And 20th Centuries

Existentialism: the view that existence precedes essence, that there's no meaning or value or truth to life a priori. Kierkegaard, reputed "founder" of existentialism: dread and anxiety make us aware of Being; in "fear and trembling" we grasp the meaning of existence and of death. Kierkegaard's answer: faith in God, who can deliver us from our forlornness. Heidegger: idea of death provokes a fear of nothingness; people hide in inauthentic routines; they seek to renounce their freedom to act. We're essentially alone, says Heidegger; we come into the world alone and exit it alone. Sartre: human beings are unique because they can both act and be aware of it at the same time. Anything we do can be the object of conscious awareness; deep fear that others will relate to us as if we were objects, reduce us to no-thing. There is no meaning to our life a priori, so the deepest striving is to define ourselves in a random and contingent world. This causes anxiety, as does the inevitable fact of death. Existentialist themes brilliantly captured in the following novels: Kafka's The Trial, Hesse's Steppenwolf, and Sartre's Nausea. Nihilism: from the Latin nihil, meaning "nothing"; rejection of claims to truth, to right and wrong, to purpose and meaning in the world. Spirit of nihilism best laid out in Nietzsche's The Will To Power. Nietzsche distinguished master morality from slave morality; Christianity, among other religions, falling into the latter category (the morality of weakness). Nietzsche: Neither truth nor facts exist; everything is interpretation. Only hope for humanity going forward is to transcend influence of religion and bad philosophy and embrace the Ubermensch, a vaguely defined hero with markedly powerful traits (the mix of apollonian and dionysian traits: e.g., the intellect of Shakespeare, the will of Napoleon).

American Philosophy (Peirce, James, Royce, Santayana, Dewey, among others)

19th And 20th Centuries

C.S. Peirce gives birth to pragmatism (doctrine which sees truth as the effectiveness of an idea used as an hypothesis; test of truth is whether idea works when tested by experiment); William James elaborates upon the doctrine (metaphysics the enemy of a pragmatist; goal of pragmatism to be clear and precise in one's thinking; doctrine is empirical in nature). With its emphasis on the practical, its instrumentalism, pragmatism seems the perfect fit for Industrial America. James makes landmark contributions in psychology (Principles of Psychology), in epistemology and morals (The Will To Believe), and in religious studies (Varieties of Religious Experience). James argues passionately in favor of religious faith. George Santayana the odd philosopher out here: born in Spain, grew up in Boston, he was influenced mostly by the Greeks (especially Plato) and by Spinoza; he loathes the pragmatist doctrine but still sees himself, at bottom, as a materialist. Chief works from Santayana (critical works such as Egotism in German Philosophy, the 5-volume Life of Reason, and the 4-volume Realms of Being). Perhaps the most articulate philosopher of the English language (unfortunate that the world only remembers GS by one aphorism: "those who cannot remember the past are doomed to repeat it"). Dewey another pragmatist, but didn't share James' fondness for religion or Peirce's interest in metaphysical criticism. Dewey most famous for his progressive contributions to education and his outspoken criticism of American culture. His main works: Democracy and Education, Human Nature and Conduct, and The Quest For Certainty.

Modern Period / Present

20th And 21st Centuries

Dominant philosophical strands: pragmatism, analytical philosophy, existentialism, nihilism, postmodernism.