Aristotle’s Contributions to Science and Western Thought

Aristotle of Stagira (384–322 BCE) was one of the most important intellectuals in the history of Western civilization. A student of Plato, the tutor of Alexander the Great, and the founder of the Lyceum in Athens, Aristotle wrote treatises on logic, metaphysics, ethics, politics, rhetoric, poetry, biology, zoology, psychology, physics, astronomy, and meteorology. His works were the foundation of the Western intellectual tradition for almost two thousand years, and they continued to be studied, commented on, and adapted well into the modern era. The Roman philosopher Cicero called Aristotle “a man of infinite learning” and “the prince of philosophers.”

This page is a concise introduction to Aristotle’s contributions to science and Western thought. It links back to the Greek Philosophy cluster, the Plato’s Theory of Forms page, and the Who Was Socrates? page.

Aristotle’s Life

Aristotle was born in 384 BCE in Stagira, a Greek town in the kingdom of Macedon in northern Greece. His father, Nicomachus, was the court physician of the Macedonian king Amyntas II, and Aristotle probably received some early training in medicine and biology. After the death of his father, Aristotle was sent to Athens to study at Plato’s Academy, where he remained for twenty years (until Plato’s death in 348 BCE).

After leaving the Academy, Aristotle spent several years in Assos and Lesbos, where he did much of his biological research, and then in Macedonia, where he became the tutor of the young Alexander (the future Alexander the Great). In 335 BCE, Aristotle returned to Athens and founded his own school, the Lyceum, in a grove dedicated to Apollo Lyceus. The Lyceum had a museum, a library, and a research collection of biological specimens, and it became one of the great intellectual centers of the ancient world.

Aristotle spent the last thirteen years of his life in Athens. After the death of Alexander in 323 BCE, anti-Macedonian feeling rose in Athens, and Aristotle was charged with impiety (in part, it was said, because of his association with Alexander). He withdrew to Chalcis in Euboea, “lest the Athenians should sin twice against philosophy,” and died there in 322 BCE, at the age of sixty-two.

Logic and Metaphysics

Aristotle invented formal logic in the Organon (“Instrument”), a collection of six treatises on reasoning. His most famous contribution is the theory of the syllogism, a form of argument in which the conclusion follows necessarily from two premises. The classic example:

All men are mortal. (Major premise) Socrates is a man. (Minor premise) Therefore, Socrates is mortal. (Conclusion)

Aristotle’s analysis of the syllogism laid the foundation of Western logic for more than two thousand years, until the development of modern symbolic logic in the nineteenth century by Frege, Boole, and Russell.

In his Metaphysics, Aristotle developed a sophisticated system of philosophical vocabulary and argument. He formulated the law of non-contradiction, the law of excluded middle, and the principle that every change has a cause. He developed the doctrine of the Four Causes (material, formal, efficient, and final), and he proposed a theory of substance in which the individual substance (the ousia) was the fundamental reality.

Biology and Natural History

Aristotle was one of the greatest biologists of antiquity. He founded the systematic study of zoology, made careful observations of the anatomy and behavior of animals, and classified the animals known to him in a way that was not improved upon until the eighteenth century.

Aristotle’s most important biological work is the History of Animals, a kind of natural history of the known animal world. He described about 500 species (some 90 of which are now extinct), and he was the first to use careful observation and dissection to study their anatomy. His Generation of Animals developed a theory of reproduction that combined careful empirical observation with a wrongheaded theory of inheritance (he thought the mother provided the matter and the father provided the form). His Parts of Animals offered a teleological account of the structure of animals, and his On the Soul (De Anima) laid the foundations of what we now call psychology.

Aristotle’s biology was the standard text in European universities until the seventeenth century. His work was eventually superseded by the work of William Harvey (on the circulation of the blood), the development of the microscope, and the rise of modern evolutionary theory.

Ethics and Politics

Aristotle’s two most famous works in practical philosophy are the Nicomachean Ethics and the Politics. In the Nicomachean Ethics, Aristotle argues that the goal of human life is eudaimonia — usually translated as “happiness” or “flourishing” — and that this is achieved by living a life of virtue, in accordance with reason, in a community of friends and family. The virtuous person, for Aristotle, is the one who finds the mean between extremes: courage is the mean between cowardice and rashness, generosity between miserliness and wastefulness, and so on.

In the Politics, Aristotle analyzes the different forms of government (monarchy, aristocracy, polity, democracy, oligarchy, and tyranny) and argues that the best form of government is a constitutional polity in which the middle class is dominant. The Politics was the most influential political treatise of the medieval and early modern world, and it shaped the development of constitutional government in the West.

Rhetoric and Poetics

Aristotle’s Rhetoric is the first systematic treatise on the art of persuasion. Aristotle defines rhetoric as “the faculty of observing in any given case the available means of persuasion,” and he analyzes the three types of appeal (ethos, pathos, logos) that have been the standard framework for the analysis of rhetoric ever since.

Aristotle’s Poetics is the first systematic treatise on literary criticism. The most famous idea in the Poetics is the theory of tragedy, in which Aristotle defines tragedy as “an imitation of an action that is serious, complete, and of a certain magnitude,” with a beginning, a middle, and an end. He also develops the concept of catharsis (the emotional purgation of the audience by the action of the tragedy), and the doctrine of the three unities (of action, time, and place) that would later dominate European drama.

The Legacy of Aristotle

Aristotle’s works were preserved by his successors at the Lyceum, edited by Andronicus of Rhodes in the first century BCE, and used as the standard texts in the great library of Alexandria. They were translated into Latin in the Middle Ages, and they formed the core of the curriculum of the medieval universities (the trivium of grammar, logic, and rhetoric, and the quadrivium of arithmetic, geometry, astronomy, and music). The rediscovery of Aristotle in the twelfth and thirteenth centuries led to the great Scholastic syntheses of Albert the Great and Thomas Aquinas. In the Renaissance, his works were edited and commented on by humanist scholars, and they were the foundation of the new natural philosophy of the seventeenth century.

The history of Western thought can, in many ways, be told as a series of responses to Aristotle. The Stoics, the Epicureans, and the Skeptics of the Hellenistic period all engaged with his work. The medieval Scholastics built on it. The Renaissance humanists criticized parts of it. The founders of modern science (Copernicus, Galileo, Harvey) accepted some of his work and rejected other parts. The philosophers of the modern period (Descartes, Spinoza, Leibniz, Kant, Hegel) all built on or reacted against his ideas. The breadth and depth of Aristotle’s influence on Western thought is, quite simply, without parallel in the history of human intellectual life.