1590s, "affecting the emotions or affections, moving, stirring" (now obsolete in this broad sense), from French pathétique "moving, stirring, affecting" (16c.), from Late Latin patheticus, from Greek pathetikos "subject to feeling, sensitive, capable of emotion," from pathetos "liable to suffer," verbal adjective of pathein "to suffer" (from PIE root *kwent(h)- "to suffer").
The specific meaning "arousing pity, sorrow, or grief" or other tender feelings is from 1737. The colloquial sense of "so miserable as to be ridiculous" is attested by 1937. Related: Pathetical (1570s); pathetically. The pathetic fallacy (1856, first used by Ruskin) is the attribution of human qualities to inanimate objects.
Proto-Indo-European root meaning "to suffer."
It forms all or part of: anthropopathy; antipathy; apathy; empathy; idiopathy; nepenthe; osteopathy; -path; pathetic; -pathic; patho-; pathogenic; pathognomonic; pathology; pathos; -pathy; psychopathic; sympathy.
It is the hypothetical source of/evidence for its existence is provided by: Greek pathos "suffering, feeling, emotion, calamity," penthos "grief, sorrow;" Old Irish cessaim "I suffer;" Lithuanian kenčiu, kentėti "to suffer," pakanta "patience."
1909, from empathy on model of sympathetic and said to have been originally meant to be distinct from empathic. A 1918 article in The Journal of Abnormal Psychology (vol. XIII) emphatically recommended empathic:
Sympathetic, the adjective, seems to have built up—so philologists say—on the analogy of pathetic: that is, sympathetic ought to be sympathic as indeed in some languages it becomes. And a little of the pathos of pathetic has usually clung to sympathetic. As for empathy, however, the adjective empathic seems to be more suitable than empathetic, if only because the latter would even more damagingly suggest pathos. [E.E. Southard]
Related: Empathetically.
"The measure soon ceases to be Spenser's except in its mere anatomy of rhyme-arrangement" [Elton, "Survey of English Literature 1770-1880," 1920]; it is the meter in Butler's "Hudibras," Scott's "Lady of the Lake," and notably the "Childe Harold" of Byron, who found (quoting Beattie) that it allowed him to be "either droll or pathetic, descriptive or sentimental, tender or satirical, as the humour strikes me; for, if I mistake not, the measure which I have adopted admits equally of all these kinds of composition."
Old English sæd "sated, full, having had one's fill (of food, drink, fighting, etc.), weary of," from Proto-Germanic *sathaz (source also of Old Norse saðr, Middle Dutch sat, Dutch zad, Old High German sat, German satt, Gothic saþs "satiated, sated, full"), from PIE *seto-, from root *sa- "to satisfy." Related: Sadder; saddest.
In Middle English and into early Modern English the prevailing senses were "firmly established, set; hard, rigid, firm; sober, serious; orderly and regular," but these are obsolete except in dialect. The sense development seems to have been via the notion of "heavy, ponderous" (i.e. "full" mentally or physically), thus "weary, tired of." By c. 1300 the main modern sense of "unhappy, sorrowful, melancholy, mournful" is evident. An alternative course would be through the common Middle English sense of "steadfast, firmly established, fixed" (as in sad-ware "tough pewter vessels") and "serious" to "grave." In the main modern sense, it replaced Old English unrot, negative of rot "cheerful, glad."
By mid-14c. as "expressing or marked by sorrow or melancholy." The meaning "very bad, wicked" is from 1690s, sometimes in jocular use. Slang sense of "inferior, pathetic" is from 1899; sad sack is 1920s, popularized by World War II armed forces (specifically by cartoon character invented by Sgt. George Baker, 1942, and published in U.S. Armed Forces magazine "Yank"), probably a euphemistic shortening of the common military slang phrase sad sack of shit.