from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A set of principles for use in scientific or philosophical investigation.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A set of principles that are used in science or philosophy.
- n. The name given by Aristotle's followers to his six works on logic.
from the GNU version of the Collaborative International Dictionary of English
- n. An organ or instrument; hence, a method by which philosophical or scientific investigation may be conducted; -- a term adopted from the Aristotelian writers by Lord Bacon, as the title (“Novum Organon”) of part of his treatise on philosophical method.
from The Century Dictionary and Cyclopedia
- n. An organ; an instrument.
- n. An instrument of thought.
- n. Hence A code of rules or principles for scientific investigation.
- n. Also organum.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a system of principles for philosophic or scientific investigations; an instrument for acquiring knowledge
He defines logic as being neither a science nor an art, but, in keeping with the traditional meaning of the word organon, just an instrument
 On the word organon, a tool, as used of the Word of God, cf. Nestorius in Marius Merc.
Knowledge is here considered from the practical point of view, as a weapon in the struggle for life, as an "organon" which has been continuously in use for generations.
Beyond the general principle of utility, therefore, we have to consider the 'organon' constructed by him to give effect to a general principle too vague to be applied in detail.
The term (Latin super = above; Greek organon = tool) was coined in 1911 by the great American ant expert and biologist William Morton Wheeler (1865–1937) in an essay titled “The Ant-Colony as an Organism” and is defined as “a collection of single creatures that together possess the functional organization implicit in the formal definition of organism.”
Rather, he appears to have seen it as an organon for the acquisition of knowledge from unquestionable first principles; in addition he wanted to use it in order to help make clear the epistemic foundations on which our knowledge rests.
To use Stumpf's terms, they are the atrium and the organon of all sciences and of philosophy.
In his systematic work on logic he pleaded for a unity of logic and metaphysics as found in the Aristotelian organon.
Is it not that this is the master organon for giving men the two precious qualities of breadth of interest and balance of judgment; multiplicity of sympathies and steadiness of sight?
Most Neoplatonists followed Alexander of Aphrodisias in regarding logic not as a separate philosophical discipline (the Stoic view) but rather as philosophy's tool, its organon.