early 15c., "periodical payment; soldier's pay," from Latin stipendium "tax, impost, tribute," in military use "pay, salary," from stips "alms, small payment, contribution of money, gift" + pendere "to hang, cause to hang; weigh; pay" (from PIE root *(s)pen- "to draw, stretch, spin"). According to Klein's sources, the first element is related to Latin stipes "log, stock, trunk of a tree" (see stipe). For the financial sense of the Latin verb, see pound (n.1). As a verb from late 15c.
1897, from German Lumpenproletariat, coined by Marx, who used it in the sense of "the rabble, poorest of the working class," "who make no contribution to the workers' cause" [OED]. From German lump "ragamuffin," which is related to lumpen "a rag, tatter," probably ultimately related to English lump (n.). With proletariat.
Marx used it first, apparently, in 1850 in German newspaper articles collected and republished in 1895 as "Die Klassenkämpfe in Frankreich 1848-1850." Its secondary sense of "boorish, stupid people" led to lumpen- being taken as a word-forming element meaning "unenlightened."
The Norse word also is cognate with Old English læn "gift," which according to OED did not survive into Middle English, but its derived verb lænan is the source of lend (v.). From early 15c. as "a contribution to public finances" (ostensibly voluntary but often coerced; sometimes repaid, sometimes not). As a verb, loan is attested from 1540s, perhaps earlier, and formerly was current, but it has now been supplanted in England by lend, though it survives in American English. Slang loan shark first attested 1900 (see shark (n.)).
c. 1300, philosophie, "knowledge, learning, scholarship, scholarly works, body of knowledge," from Old French filosofie "philosophy, knowledge" (12c., Modern French philosophie) and directly from Latin philosophia, from Greek philosophia "love of knowledge, pursuit of wisdom; systematic investigation," from philo- "loving" (see philo-) + sophia "knowledge, wisdom," from sophis "wise, learned;" a word of unknown origin [Beekes]. With many spelling variants in Middle English (filozofie, phelosophie, etc.).
From mid-14c. as "the discipline of dealing in rational speculation or contemplation;" from late 14c. as "natural science," also "alchemy, occult knowledge;" in the Middle Ages the word was understood to embrace all speculative sciences. Meaning "system a person forms for conduct of life" is attested from 1771. The modern sense of "the body of highest truth, the science of the most fundamental matters" is from 1794.
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]