John Buridan

Life and Intellectual Context

John Buridan (Latin: Johannes Buridanus) was a prominent fourteenth‑century philosopher associated with the University of Paris, where he studied and then taught for most of his career. Born around 1300, probably in the region of Artois in northern France, he belonged to the generation after William of Ockham and before later Parisian masters such as Nicole Oresme.

Buridan studied in the arts faculty, the lower faculty that prepared students for advanced study in theology, law, or medicine. Unlike many of his contemporaries, he appears never to have proceeded to the theology faculty or taken a doctorate in theology. Instead, he remained a master of arts, serving multiple terms as rector of the University of Paris. This unusual career path indicates both his institutional importance and the growing prestige of the arts faculty in the fourteenth century.

His philosophical work is preserved primarily in commentaries on Aristotle (particularly the Organon, Physics, De anima, and Ethics) and in independent logical treatises such as the Summulae de dialectica. While many biographical anecdotes about Buridan—especially the colorful legends involving Queen Jeanne of Navarre—are considered apocryphal, they reflect his later reputation as a vivid and independent personality.

Buridan died in Paris sometime between about 1358 and 1361. His students and followers carried his ideas throughout Europe, especially to universities in central and eastern Europe, where “Buridanism” became a recognizable current of late medieval philosophy.

Logic and Philosophy of Language

Buridan’s most sustained work is in logic and the philosophy of language, where he stands as one of the leading representatives of the via moderna (“modern way”) of scholastic thought.

His major logical work, the Summulae de dialectica, reworked a traditional textbook genre into an original and systematic treatment. In it, Buridan combines technical analysis with attention to ordinary reasoning, aiming to show how logical tools clarify everyday and scientific discourse.

Central to his approach is an account of supposition theory—a medieval form of semantic theory concerned with how terms stand for things in propositions. Buridan distinguishes, analyzes, and systematizes different kinds of supposition (such as personal, simple, and material) to explain how terms like “man” can refer sometimes to individual human beings, sometimes to a universal concept, and sometimes to the word “man” itself. This framework allowed him to tackle semantic paradoxes and issues surrounding quantification, reference, and truth conditions in a precise, rule‑governed way.

Buridan is often placed within a broadly nominalist tradition. While he does not simply repeat Ockham’s views, he shares the tendency to treat universals as entities existing only in the mind, rather than as independently existing forms. For Buridan, mental language—the system of concepts in the mind—plays a foundational role: spoken and written languages are conventional signs for mental terms, which in turn have a natural semantic relation to things in the world.

Within this framework he developed subtle positions on:

• Logical consequence and validity, offering refined criteria for when an inference holds in virtue of its form.
• Modal logic, discussing necessity and possibility in relation to God’s power and the contingency of created things.
• Semantic paradoxes, including versions of the Liar paradox, which he approached by restricting how certain self‑referential sentences can be used to assert truth.

Buridan’s logical writings were influential in shaping late medieval pedagogy; they served as standard textbooks across European universities and contributed to the emerging tradition of rigorous, formally oriented scholastic logic.

Natural Philosophy and Impetus Theory

In natural philosophy, Buridan is best known for his impetus theory, formulated primarily in his commentaries on Aristotle’s Physics and On the Heavens. Seeking to explain projectile motion and celestial dynamics more adequately than traditional Aristotelian accounts, he argued that a mover imparts to a body a certain impetus—a quality or disposition that keeps it in motion without continuous contact.

On Buridan’s account:

• A moving body carries an impressed impetus proportional to its speed and quantity of matter.
• This impetus is gradually diminished by resistance (such as air resistance and the body’s own gravity), eventually allowing natural tendencies (e.g., descent) to dominate.
• In the absence of sufficient resistance, as with celestial bodies, impetus can remain effectively undiminished, so that the heavenly spheres continue in perpetual motion once set in motion by God.

This theory adapts Aristotelian concepts but moves toward a more inertial understanding of motion. Historians of science have debated how far Buridan’s ideas prefigure early modern mechanics; many regard them as an important bridge between ancient kinematics and later formulations by figures such as Galileo and Newton, while emphasizing that Buridan still operates within an Aristotelian conceptual framework.

Buridan also engaged with issues in cosmology, optics, and psychology (in the Aristotelian sense, dealing with the soul and cognition). His commentary on De anima examines perception, imagination, and intellect, again using his theory of mental language to articulate how the mind represents external objects.

The popular phrase “Buridan’s ass”, describing a donkey starving between two equally attractive haystacks because it cannot choose, is often associated with him, though there is no clear textual evidence that he formulated this specific example. Related discussions of indifference of the will and choice between apparently equal goods do occur in his writings and in the broader scholastic context, and later authors attached the image of the ass to his name.

Ethics, Influence, and Legacy

In ethics, particularly in his commentary on Aristotle’s Nicomachean Ethics, Buridan treats moral philosophy as an analysis of human happiness, virtue, and rational choice, integrating classical themes with Christian doctrine. He emphasizes the role of practical reason in ordering desires and actions, and he discusses the will’s freedom in terms that allow for genuine contingency in human decisions while maintaining God’s foreknowledge and providence.

His ethical views are marked by:

• A focus on habit and character as central to moral life.
• An interest in moral psychology, examining how intellect and will cooperate or conflict.
• Attempts to reconcile Aristotelian eudaimonism (happiness as flourishing) with Christian beatitude (ultimate fulfillment in God).

Buridan’s broader influence was substantial across late medieval and early Renaissance Europe. His logical texts shaped curricular standards at Paris and beyond; his students and readers helped disseminate a distinctively “Buridanian” approach, characterized by precise argumentation, semantic awareness, and a willingness to revise Aristotelian doctrines to accommodate empirical observation and internal consistency.

In the history of philosophy, Buridan is often viewed as:

• A central figure of the late medieval via moderna, alongside Ockham.
• An important contributor to the prehistory of modern science, especially in the theory of motion.
• A key architect of sophisticated semantic and logical theories that influenced post‑medieval logical traditions.

Modern scholarship, especially since the twentieth century, has progressively reassessed Buridan, moving from treating him as a transitional thinker to recognizing him as an original philosopher in his own right. His writings now serve as crucial sources for understanding the evolution of logic, natural philosophy, and ethics in the centuries immediately before the scientific and philosophical transformations of the early modern period.