Pythagoras of Samos (569 BC - 475 BC): A Greek mathematician and philosopher of almost mythic proportions, he taught that numbers are the essence of all reality. He is remembered chiefly for the Pythagorean theorem, which had been known for a thousand years already when Pythagoras was born. Mises adduces that theorem as an example of an apodictic truth, much like Ricardo's law of comparative cost.
Heraclitus of Ephesos (535 BC - 475 BC): A Greek philosopher of great originality. He taught that all the world is in flux, and that the true underlying reality is an eternal fire. Interestingly, legend has it that he died in a pile of manure while trying to burn an illness out of his body. Mises mentions his name, erroneously, when discussing peace as the foundation of society -- at least, I can't find the "quote" Mises used among the 124 fragments that scholars attribute to Heraclitus.
Aristotle (384 BC - 322 BC): Greek teacher and philosopher. Born in Macedonia, Aristotle was educated in Athens, where he was for many years a student of Plato. After a brief return to Macedonia to tutor Alexander the Great, Aristotle founded his own school of philosophy in Athens. A prolific author, he wrote on a wide variety of subjects -- from zoology and botany to physics, logic, and metaphysics. The Scholastic theologians drew heavily on his Metaphysics, retarding the progress of empirical inquiry during the Middle Ages. Mises mentions Aristotle's objective theory of economic values, which stifled innovation in economics for thousands of years.
Scholastics: Also known as the schoolmen, these Roman Catholic theologians / philosophers dominated European intellectual life during the early medieval period, or, roughly, from 1000 AD until the mid-15th century. The overthrow of Scholasticism by early scientific thinkers like Copernicus, Tycho Brahe, and Galileo marked the beginning of the Renaissance, which coincided, very nearly, with the heresies of Luther and Calvin, and the Protestant Reformation.
Prominent scholastics included Albertus Magnus, Peter Lombard, St. Thomas Aquinas, William of Ockham, and Roscellinus. Mises refers to the Scholastics and scholasticism frequently. Not only did their devotion to Aristotelian and Biblical dogmas retard the progress of empirical science; their metaphysical excesses also sparked an intellectual reaction that threw the introspective procedure native to praxeological inquiry into ill repute, retarding the progress of economic science in the 19th and 20th centuries.
St. Francis d'Assisi (1181 - 1226): Umbrian (central Italian) mystic, sage, and saint. The scion of a noble family, Francis was a warrior in his youth. But he eventually had a mystical experience and began a life of asceticism. A Catholic order, the Franciscans, is named after him. He is also remembered for his vow of poverty, and for his miraculous friendships with birds and animals of every description. Mises mentions him as an example of a sincere religious ascetic.
Santa Clara (Sciffi) (1194 - 1253): Another saint from Umbria. She joined St. Francis at the age of 18, and with his advice and encouragement founded another order (of nuns) known as the Poor Ladies, or the Poor Clares. Mises mentions her name as another example of a person not consumed by ordinary, or mundane, desires.
Thomas Aquinas (1225 - 1274): Neapolitan theologian, author, and philosopher. Thomas took holy orders against the wishes of his father, a nobleman, and studied under Albertus Magnus. Thoroughly Arisototelian in his outlook, Thomas produced many hermeneutic and exegetical works. His final work, Summum, describes the then prevailing doctrines of the Roman Catholic Church in considerable detail (God, the prime mover, as perfect Love; the Beatific Vision as man's highest calling; Christ as the perfect Soul in an imperfect Body; etc). Many of his teachings are still the official dogma of the Church today. Mises doesn't mention St. Thomas directly, but alludes to him when speaking of medieval Scholasticism and the scholarly confusion that movement spawned.
William of Ockham (1300? - 1349): English Nominalist philosopher; a prominent scholastic, or schoolman. William revived the doctrine of Nominalism. He was, for a time, head of the Franciscan order. He is remembered today for Ockham's razor, a principle of logic which states that entities (or hypotheses, or reasons) ought not be multiplied unnecessarily. In other words, when two explanations are available, prefer the simpler one. Mises doesn't mention William directly, but he does refer to Realism, Nominalism, and Scholasticism.
Nicolas Copernicus (1473 - 1543): Polish astronomer who overthrew the Ptolemaic, or Earth-centered, view of the solar system and set in motion a train of events leading from the observations of Galileo and Tycho Brahe through the theories of planetary motion advanced by Johannes Kepler and culminating in the invention of the differential calculus and the discovery of the law of universal gravitation by Sir Isaac Newton within 150 years of Copernicus' death. Trained first in mathematics and optics at Cracow, Nicolas traveled in 1496 to Bologna, where he took up the study of the canon law. His astronomical observations evidently commenced while he was in Italy. Returning north, to Prussia, in 1505, he continued his astronomical observations, which for many years were interspersed with his official duties as a judge, tax collector, physician, and military governor. His masterpiece, De Revolutionibus, was complete by 1530, but publication was delayed until his death in 1543, primarily because he feared persecution by the Church. Mises mentions him, along with Galileo and Lavoisier, as an innovator -- an original thinker whose ideas sounded "crazy" when they were first advanced, but which later came to be accepted as the conventional wisdom.
Galileo Galilei (1564 - 1642): Tuscan physicist and astronomer. A student at first of medicine, Galileo quickly became disgusted with Aristotelianism and set out to discover the truth for himself. His unpopularity with the faculty of the university at Pisa grew rapidly after his famous experiment with falling bodies showed that heavy -- or dense -- bodies fall to the ground at the same rate as lighter -- or less dense -- bodies do, thus contradicting a central tenet of Aristotle's "physics." Under political pressure he moved to Padua (1592), where his lectures on mathematical and physical principles attracted students from all of Europe. By 1610 he was using a refracting telescope to observe the solar system -- he is credited with discovering the four largest moons of Jupiter in that year. In 1613 he published a treatise endorsing the Copernican, or heliocentric, view of the solar system, and his political difficulties with the Holy Roman Catholic Church were off and running at full speed. Forced to recant in 1616, and again in 1632, Galileo never deserted his quest for the truth about physical reality. His inquiring mind and dedication to experimental verification fueled the Renaissance and the rise of rationalism, leading directly to the current ascendancy of science and technology in Western civilization. Mises mentions him, along with Copernicus and Lavoisier, as an innovator -- an original thinker whose ideas sounded "crazy" when they were first advanced, but which later came to be accepted as the conventional wisdom.
John Locke (1632 - 1704): English philosopher and physician. Educated at Oxford, he early displayed a propensity for free and original thought by rebelling against the prevailing currents of scholasticism and Aristotelianism. The execution of Charles I in 1649 exerted a profound influence on his political views. In 1667 he entered the personal medical service of Anthony Ashley Cooper, who was later (1672) created 1st Earl of Shaftesbury. Locke's subsequent career was thus intimately tied to the fortunes of the Earl, who fell from favor in 1682 when James II (the last Stuart king in Great Britain) discovered his involvement in the attempted coup d'etat staged by the Duke of Monmouth. Thereafter Locke spent several years in Holland, but soon after the "glorious revolution" of 1688 he returned to England.
Generally regarded as the founder -- along with Francis Bacon -- of British Empiricism, Locke's philosophy and polemics are interesting and powerful. The political theory expressed in the Second Treatise on Civil Government (which was published anonymously in 1689) was accepted wholeheartedly by Thomas Jefferson, who incorporated it in the Declaration of Independence. And the epistemological theory advanced in Locke's Essay Concerning Human Understanding (1690) -- that the human mind is a tabula rasa, or blank slate, and that all human knowledge is directly rooted in experience -- has exerted a tremendous influence on philosophy, and on psychology, ever since. Mises cites Locke's Essay as the source of a fundamental praxeological notion: that all human action is motivated by some sense of uneasiness.
I admire John Locke's philosophy. Click here to read my favorite bit from his Essay Concerning Human Understanding, and some very interesting material from Some Observations on the Conduct of the Understanding in the Pursuit of Truth.
François Quesnay (1694 - 1774): French physician and political economist. Together with Gournay he founded the Physiocrats, who are generally recognized as the first truly scientific school of economic thought. His Tableau économique was the first graphic presentation of the circulation of money throughout an entire economic system. Quesnay served as a medical officer in the courts of Louis XV and his grandson Louis XVI. His friend Turgot actually put some of Quesnay's ideas into practice in the year of the elderly doctor's death. Mises doesn't mention Quesnay directly, but does acknowledge the Physiocrats, along with the classical British economists, as the founders of economic science.
Richard Cantillon (1697 - 1734): French financier, businessman, and economist. His Essai sur la nature du commerce in général (1755) is a very early treatise on economics that probably served as source material for Adam Smith. Mises mentions him in passing as one of the founders of economic science.