In this section, Bacon describes four “idols”—sources of flawed thinking that harm humanity’s quest for knowledge. He warns that they must be guarded against during the “instauration.” Aphorisms 41-44 briefly introduce each idol, and subsequent sections expand upon them individually, including examples of them.

Aphorisms 45-52 elaborate on the “Idols of the tribe,” or innate human fallibility. Bacon gives examples, such as the tendency to jump to conclusions in excitement or the inclination to look for order or patterns in things where there might not be any—for instance, trying to impose perfect circles onto astronomical orbits.

Aphorisms 53-58 elaborate on the “Idols of the den”—the individual’s particular flaws and biases, whether innate to the person or arising from external influence. An example is how some people are inclined to primarily look to the past, specifically antiquity, while some are too blinkered in looking forward toward novelty; few manage to balance these perspectives.

Aphorisms 59-60 expand on the “Idols of the marketplace,” which are the errors that arise in human communication, including confusion or deception. Bacon asserts that words not only communicate human thoughts but also shape them, being the medium in which thoughts are formed. He specifically mentions “names,” or nouns, describing how they can give a misleading impression of what something actually is.