experimentation alone, not chance observation, is worthy of confidence. Instead of the customary divorce of experience and understanding, a firm alliance, a "lawful marriage," must be effected between them. The empiricists merely collect, like the ants; the dogmatic metaphysicians spin the web of their ideas out of themselves, like the spiders; but the true philosopher must be like the bee, which by its own power transforms and digests the gathered material.
As the mind, like a dull and uneven mirror, by its own nature distorts the rays of objects, it must first of all be cleaned and polished, that is, it must be freed from all prejudices and false notions, which, deep-rooted by habit, prevent the formation of a true picture of the world. It must root out its prejudices, or, where this is impossible, at least understand them. Doubt is the first step on the way to truth. Of these Phantoms or Idols to be discarded, Bacon distinguishes four classes: Idols of the Theater, of the Market Place, of the Den, and of the Tribe. The most dangerous are the idola theatri, which consist in the tendency to put more trust in authority and tradition than in independent reflection, to adopt current ideas simply because they find general acceptance. Bacon's injunction concerning these is not to be deceived by stage-plays (i.e., by the teachings of earlier thinkers which represent things other than they are); instead of believing others, observe for thyself! The idola fori, which arise from the use of language in public intercourse, depend upon the confusion of words, which are mere symbols with a conventional value and which are based on the carelessly constructed concepts of the vulgar, with things themselves. Here Bacon warns us to keep close to things. The idola specus are individual prepossessions which interfere with the apprehension of the true state of affairs, such as the excessive tendency of thought toward the resemblances or the differences of things, or the investigator's habit of transferring ideas current in his own department to subjects of a different kind. Such individual weaknesses are numberless, yet they may in part be corrected by comparison with the perceptions of others. The idola tribus, finally, are grounded in the
