Newton's great physics book called itself philosophy, and nobody found that strange
Isaac Newton titled his 1687 masterpiece Mathematical Principles of Natural Philosophy. Today we file it under physics. For most of history philosophy covered nearly every kind of rational inquiry, and its branches kept leaving home to become sciences, which is why it has been nicknamed the midwife of the sciences.
The word comes from Greek philosophía, love of wisdom, joining phílos, friend or lover, with sophía, wisdom. Some sources credit Pythagoras with coining it, though that is uncertain. It reached English around 1175 through Old French and Anglo-Norman. Only toward the end of the modern period did the term shrink to its present sense, centred on metaphysics, epistemology, ethics and logic, and set apart from mathematics and the empirical sciences.
Defining it remains contested. Immanuel Kant tied the whole subject to four questions, about the limits of knowledge, how to act, what to hope for, and what a human being is. W. V. O. Quine saw it as an abstract but empirical science of broad patterns, which invites the awkward question of why it has not progressed the way physics has. Ludwig Wittgenstein treated it as therapy for confusions created by ordinary language, and Edmund Husserl wanted a rigorous science that suspends assumptions to return to things as experienced.
Older traditions stressed a way of life. The Stoics treated philosophy as mental training aimed at eudaimonia, a flourishing life. Socrates insisted the unexamined life was not worth living, and Bertrand Russell warned that someone with no philosophy lives imprisoned by the prejudices of common sense and of their era and nation.
Western philosophy began in sixth-century BCE Greece with thinkers such as Thales of Miletus, who sought rational explanations of the whole cosmos, before Socrates, Plato and Aristotle widened the questions to conduct, knowledge and mind. Other great traditions had different centres of gravity: Arabic-Persian thought wrestled with reason and revelation, Indian philosophy linked the nature of reality to the path to enlightenment, and Chinese philosophy concentrated on right conduct, government and self-cultivation.
Source: Philosophy
