- The view that absolute truth or ultimate certainty is unattainable, especially regarding knowledge not based on experience or perceivable phenomena.
- The view that the existence of God or of all deities is unknown, unknowable, unproven, or unprovable.
- Doubt, uncertainty, or scepticism regarding the existence of a god or gods.
- 1956, January 31st: Alan Alexander Milne; quoted in:
- 1988: James B. Simpson, Simpson’s Contemporary Quotations, [https://web.archive.org/web/20090122122546/http://www.bartleby.com/63/93/4393.html № 4,393] (Houghton Mifflin, ISBN 0395430852
- The Old Testament is responsible for more atheism, agnosticism, disbelief — call it what you will — than any book ever written; it has emptied more churches than all the counterattractions of cinema, motor bicycle and golf course.
- (by extension) Doubt, uncertainty, or scepticism regarding any subject of dispute.
- French: agnosticisme
- German: Agnostizismus
- Italian: agnosticismo
- Portuguese: agnosticismo
- Russian: агностици́зм
- Spanish: agnosticismo