organon
Concise Oxford English Dictionary © 2008 Oxford University Press:
organon /ˈɔːg(ə)nɒn/
▶noun a means of reasoning or a system of logic.
– origin C16: from Gk, lit. ‘instrument, organ’; Organon was the title of Aristotle's logical treatises.
'organon' also found in these Oxford entries:

