Novum Organum, or True Suggestions for the Interpretation of Nature

Does the mind meet nature cleanly, or already bent out of true? Bacon's famous diagnosis is that four kinds of illusion distort thought before inquiry even begins.

The book's most famous move is its account of the Idols — the systematic illusions that distort the mind before it reaches any evidence. There are four: those bred into the whole species, those peculiar to each person's temper and history, those bred by the slipperiness of words, and those absorbed from inherited philosophies. The point is that error is not just carelessness to be corrected case by case but a standing bias built into perception, language and tradition. Before the mind can read nature, it must first be cleared of its own idols, which is why Bacon makes this diagnosis the ground of his whole method.

• epistemology
• perception
• empiricism
• logic
• metaphysics
• nature
• scientific inquiry

How should knowledge actually be built, if not by leaping to grand principles? Bacon sets a slow induction that climbs from organized observation by measured degrees against the old logic's shortcuts.

Against the old logic, which spun broad axioms out of a few cases and then deduced the rest, Bacon sets a patient induction that climbs from organized, deliberately arranged observation to modest generalizations and only gradually to wider ones. The mind is not to jump to the highest principles but to ascend by measured degrees, checking at each step. This is method as discipline: it forbids the premature theory Bacon thought had frozen natural philosophy, and it makes experiment and the careful tabulation of instances, not clever argument, the engine of discovery.

• induction
• methodology
• scientific method
• empiricism
• experimentation
• axioms
• logic
• classification
• scientific inquiry
• causation

Can two thousand years of inherited logic simply be replaced? Bacon's title says yes: the Novum Organum is offered as a new instrument to supplant Aristotle's, and its very form is part of the argument.

The title answers a book two thousand years old — Aristotle's logical works, the Organon or instrument of reasoning — which Bacon proposed to replace outright. He wrote it not as a polished treatise but as strings of numbered aphorisms, distrusting the finished system, which he thought closed a subject before it was understood. The book was only Part Two of a vast unfinished plan, the Instauratio Magna, a rebuilding of all knowledge. The presumption is deliberate: the old instrument, Bacon argues, is exactly what has held inquiry back, so advancing knowledge means changing the tool, not merely trying harder with it.

• methodology
• logic
• natural philosophy
• scientific method
• philosophy of science
• axioms
• experimental method