Origins
The word 'autopsy' carries within it a philosophical claim about evidence and truth. Etymologically it means 'seeing for oneself' — from Greek 'autos' (self) and 'opsis' (sight, vision) — and it began not as a medical term at all but as an epistemological one. In classical Greek, 'autopsia' described the act of being an eyewitness, of gaining direct personal knowledge rather than relying on the reports of others. Herodotus and Thucydides used related words to signal that a historian had personally visited a place or witnessed an event. The autopsy, in this original sense, was a first-person validation.
The medical application emerged because the post-mortem examination is precisely this kind of direct, unmediated inquiry. When a physician wants to know what killed a patient, no symptom report, no family account, no prior diagnosis can substitute for opening the body and looking. The medical autopsy, which developed in earnest during the Renaissance as taboos on dissecting human corpses gradually relaxed, was the epistemological autopsy — seeing for oneself — applied to the interior of a dead body. The word entered medical Latin and French in the seventeenth century, and English borrowed it around the same time.
The Greek root 'opsis' (ὄψις, sight, vision, appearance) derives from PIE *okʷ- (to see, eye), one of the most productive roots in Indo-European linguistics. This root produced Greek 'ophthalmos' (eye), 'optikos' (of sight), and the suffix '-opsis' (a seeing, a sight). In Latin the root became 'oculus' (eye), giving English 'oculist,' 'binocular,' 'monocle,' and 'inoculate' (originally meaning to graft an eye-bud onto a plant). In English itself, the Old English word 'ēage' (eye) descends from the same root. The word 'window' — Old Norse 'vindauga,' wind-eye — is a poetic compound built on the same ancestral root.
Greek Origins
The prefix 'autos' (self) appears throughout English scientific vocabulary: 'automobile' (self-moving), 'autobiography' (self-life-writing), 'autonomy' (self-law), 'autopilot' (self-steering), 'automatic,' 'autograph.' The Greek prefix expresses independence and self-causation, which is why it attaches so readily to scientific and technical compounds.
The related medical term 'biopsy' (Greek 'bios,' life, + 'opsis,' sight) was coined in 1879 to name the examination of tissue taken from a living patient — a seeing of living tissue, as opposed to the autopsy's examination after death. The distinction between biopsy (living) and autopsy (dead) is thus transparently encoded in the Greek etymology of each word. 'Necropsy' (Greek 'nekros,' dead body, + 'opsis') is used specifically for animal post-mortems and is a near-synonym of autopsy in veterinary contexts.
Modern forensic pathology has made the autopsy a legal as well as medical institution. In suspicious or unexplained deaths, the autopsy provides the evidentiary foundation for criminal investigation — a function that returns the word to its Greek origin: the autopsy is the court's act of seeing for itself.