Existentialism Is a Humanism was written to correct common misconceptions about Jean-Paul Sartre's thought. Sartre, the most dominant European intellectual of the post-World War II decades, accepted an invitation to speak on October 29, 1945, at the Club Maintenant in Paris. The unstated objective of his lecture was to expound his philosophy as a form of existentialism, a term much bandied about at the time. Sartre asserted that existentialism was essentially a doctrine for philosophers, though, ironically, he was about to make it accessible to a general audience.

The published text of his lecture quickly became one of the bibles of existentialism and made Sartre an international celebrity. The idea of freedom occupies the center of Sartre’s doctrine. Man, born into an empty, godless universe, is nothing to begin with. He creates his essence—his self, his being—through the choices he freely makes (“existence precedes essence”). Were it not for the contingency of his death, he would never end. Choosing to be this or that is to affirm the value of what we choose. In choosing, therefore, we commit not only ourselves but all of mankind.

This book presents a new English translation of Sartre’s 1945 lecture and his analysis of Camus’s The Stranger, along with a discussion of these works by acclaimed Sartre biographer Annie Cohen-Solal. This edition is a translation of the 1996 French edition, which includes Arlette Elkaïm-Sartre’s introduction and a Q&A with Sartre about his lecture.

The Principia: Mathematical Principles of Natural Philosophy is Isaac Newton's monumental work, originally published in 1687. Known familiarly as the Principia, this text laid out in mathematical terms the principles of time, force, and motion that have guided the development of modern physical science.

Even after more than three centuries and the revolutions of Einsteinian relativity and quantum mechanics, Newtonian physics continues to account for many of the phenomena of the observed world. Newtonian celestial dynamics is still used to determine the orbits of our space vehicles.

This edition is a completely new translation, the first in 270 years, based on the third (1726) edition, the final revised version approved by Newton. It includes extracts from earlier editions, corrects errors found in previous versions, and replaces archaic English with contemporary prose and up-to-date mathematical forms.

Newton's principles describe acceleration, deceleration, and inertial movement; fluid dynamics; and the motions of the earth, moon, planets, and comets. A great work in itself, the Principia also revolutionized the methods of scientific investigation. It set forth the fundamental three laws of motion and the law of universal gravity, the physical principles that account for the Copernican system of the world as emended by Kepler, thus effectively ending controversy concerning the Copernican planetary system.

The illuminating Guide to the Principia by I. Bernard Cohen, along with his and Anne Whitman's translation, makes this preeminent work truly accessible for today's scientists, scholars, and students.

Thomas S. Kuhn's classic book The Structure of Scientific Revolutions is a landmark in intellectual history. It reshaped our understanding of the scientific enterprise and human inquiry in general. Kuhn challenged long-standing assumptions about scientific progress, arguing that transformative ideas don’t arise from the gradual process of experimentation and data accumulation, but instead occur outside of "normal science."

His ideas on how scientific revolutions bring order to the anomalies that amass over time in research experiments are still instructive in today’s biotech age. This essential work includes an insightful introduction by Ian Hacking, which clarifies terms popularized by Kuhn, including "paradigm" and "incommensurability," and applies Kuhn’s ideas to the science of today.

This edition is newly designed with an expanded and updated index, providing important background information as well as a contemporary context.

The Road to Serfdom is a classic work in political philosophy, intellectual and cultural history, and economics. This influential book has both inspired and infuriated politicians, scholars, and general readers for decades. Originally published in England in 1944, The Road to Serfdom offers a passionate warning against the dangers of state control over the means of production.

Friedrich A. Hayek argues that the collectivist idea of empowering government with increasing economic control would inevitably lead not to a utopia, but to the horrors experienced in Nazi Germany and Fascist Italy. First published by the University of Chicago Press on September 18, 1944, the book garnered immediate attention and popularity. The first printing of 2,000 copies sold out instantly, and within six months, more than 30,000 copies were sold.

A perennial best-seller, The Road to Serfdom has sold over a quarter of a million copies in the United States alone, not including its British edition or the many translations into languages such as German, French, Dutch, Swedish, and Japanese. It stands alongside works by Alexis de Tocqueville, John Stuart Mill, and George Orwell for its timeless meditation on the relationship between individual liberty and government authority.

This influential book continues to impact political and social climates, from the rise of socialism after World War II to the Reagan and Thatcher revolutions in the 1980s, and the transitions in Eastern Europe from communism to capitalism in the 1990s.

Summa Theologica is a monumental work by St. Thomas Aquinas that aims to summarize all human knowledge. Although such an undertaking might seem ambitious even today, this classic masterpiece remains a cornerstone in philosophical and theological literature.

Through its comprehensive examination of enduring questions, Aquinas provides timeless insights into the nature of existence, ethics, and the divine. His work continues to inspire and challenge readers, encouraging them to engage with fundamental questions that have persisted through the centuries.

This collection, spanning five volumes, delves deep into the complexities of faith and reason, offering readers a chance to explore the intricacies of medieval thought and its relevance today.