Novum Organum

A treatise in two books of numbered aphorisms, published in 1620 as the second part of Bacon's unfinished Great Instauration, his plan to rebuild all knowledge. The title answers Aristotle's logical works, known as the Organon: Bacon offers a new instrument for the mind. Book I is critical. Bacon argues that the syllogism and hasty generalisation have kept learning barren, and that human power over nature depends on knowing causes. He names four 'idols' that distort thinking: of the tribe (common to human nature), of the cave (individual quirks), of the marketplace (misleading words) and of the theatre (received philosophical systems). He compares empirics to ants, rationalists to spiders and the true philosopher to the bee, which gathers and transforms. Book II sets out his method of induction, with tables of presence, absence and degree, applied to the nature of heat, which he concludes is a kind of motion, and a long list of privileged instances.

It is the classic manifesto for experimental science, and the doctrine of the idols remains one of the clearest early accounts of how bias, language and dogma mislead us.