Francis Bacon

The subtlety of nature is greater many times over than the subtlety of the senses and understanding. The errors of the mind — the Idols of the Tribe, the Cave, the Market-place, and the Theatre — are the four chief sources of all our false opinions. We must clear the mind of these before we can see anything clearly. This is the work of philosophy before it...

Knowledge is power — not as an abstract virtue but as a practical fact. The man who understands the tides commands the harbour. The physician who understands infection prevents the plague. The engineer who understands materials builds the bridge that does not fall. All the great wonders of the world have been achieved not by men who knew more than others,...

It would be an unsound fancy and self-contradictory to expect that things which have never yet been done can be done except by means which have never yet been tried. The logic of Aristotle served well for argumentation and disputation. It does not serve for the discovery of new knowledge. We need a new logic — one that goes from particulars to axioms, from...

The idols and false notions which are now in possession of the human understanding have taken deep root. They obstruct the entrance of truth. The mind does not receive evidence like a clean mirror; it bends evidence around tribe, cave, marketplace, and theatre.

Knowledge is power. Scientia potentia est. Men have sought to know nature in order to comprehend and admire it; I propose that we know nature in order to command it. The relief of man's estate — the curing of diseases, the improvement of agriculture, the shortening of distances — is the legitimate end of science. Philosophy that produces nothing but books...