philosophy (n.) Look up philosophy at Dictionary.com
c.1300, "knowledge, body of knowledge," from Old French filosofie "philosophy, knowledge" (12c., Modern French philosophie) and directly from Latin philosophia and from Greek philosophia "love of knowledge, pursuit of wisdom; systematic investigation," from philo- "loving" (see philo-) + sophia "knowledge, wisdom," from sophis "wise, learned;" of unknown origin.
Nec quicquam aliud est philosophia, si interpretari velis, praeter studium sapientiae; sapientia autem est rerum divinarum et humanarum causarumque quibus eae res continentur scientia. [Cicero, "De Officiis"]



[Philosophical problems] are, of course, not empirical problems; but they are solved through an insight into the workings of our language, and that in such a way that these workings are recognized -- despite an urge to misunderstand them. The problems are solved, not through the contribution of new knowledge, rather through the arrangement of things long familiar. Philosophy is a struggle against the bewitchment (Verhexung) of our understanding by the resources of our language. [Ludwig Wittgenstein, "Philosophical Investigations," 1953]
Meaning "system a person forms for conduct of life" is attested from 1771.