Search results
- The phrase originates from ancient Greek mathematics and philosophy, where demonstrating conclusions through rigorous proof was essential.
library.fiveable.me/key-terms/elementary-latin/quod-erat-demonstrandum
People also ask
Where did quod erat demonstrandum come from?
Where did QED come from?
Why did Euclid use quod erat faciendum?
When was QED used in philosophy?
Salve. Quod erat demonstrandum (Q.E.D.). This Latin phrase means "what was to be demonstrated." It's used at the end of a proof or argument to show that what...
- 20 sec
- 88
- Living Latin Legacy
The phrase quod erat demonstrandum is a translation into Latin from the Greek ὅπερ ἔδει δεῖξαι (hoper edei deixai; abbreviated as ΟΕΔ). The meaning of the Latin phrase is "that [thing] which was to be demonstrated" (with demonstrandum in the gerundive).
It was invented by Aristotle (384–322 B.C.) in Athens, and recorded in a group of writings known as the Organon. In one of these works, the Prior Analytics, Aristotle attempted to provide a complete analysis of the valid forms of reasoning.
Etymology and early use. The phrase quod erat demonstrandum is a translation into Latin from the Greek Greek, Ancient (to 1453);: ὅπερ ἔδει δεῖξαι (Greek, Ancient (to 1453);: hoper edei deixai; abbreviated as ΟΕΔ). Translating from the Latin phrase into English yields "that was to be demonstrated".
These initials stand for the Latin quod erat demonstrandum meaning, ‘what was to be demonstrated’. It was coined by Euclid in Greek c. 300 BC but it is better known in its Latin translation. The expression QED is typically used by mathematicians and philosophers to conclude proofs and arguments.
The earliest known use of the phrase quod erat demonstrandum is in the early 1600s. OED's earliest evidence for quod erat demonstrandum is from 1614, in the writing of William Bedwell, Arabist and mathematician.
The phrase originates from ancient Greek mathematics and philosophy, where demonstrating conclusions through rigorous proof was essential. In modern usage, Q.E.D. is still seen in academic writing, especially in mathematics, to affirm the validity of a proof.
