Skip to main content


Francis Bacon’s 400-year-old list of scientific foibles holds lessons for modern scientists

Novum Organum

Francis Bacon
Purchase this item now

In the early 17th century, the English philosopher and statesman Francis Bacon envisioned a bold, multiphase program to accumulate knowledge of the natural world. A critical part of this plan was Novum Organum, which celebrates its 400th anniversary this year. In this work, Bacon attempted to undo the centuries-old dominance of Aristotelian forms of inquiry, encouraging readers to instead apply inductive reasoning to carefully curated observations of the natural world.

“Book One” of Novum Organum addressed why so little progress had thus far been made in understanding nature. Here, Bacon cautioned against “idols and false notions” that can interfere with the quest for scientific knowledge, providing the first and possibly the most comprehensive catalog of human foibles that can threaten the integrity of science.

Bacon referred to these shortcomings as “Idols” of “the Tribe,” “the Cave,” “the Marketplace,” and “the Theater.” The “Idols of the Tribe” are the tendencies of the mind to leap to incorrect conclusions, for example, our inclination “to suppose the existence of more order and regularity in the world” than is actually there. To combat a prominent Idol of the Tribe—the tendency to seek and be moved by confirmatory evidence more so than by disconfirmatory evidence (what we now call confirmation bias)—Bacon directed the scientist to construct a “Table of Deviations, or of Absence in Proximity” that documents observations that are similar to an affirmative but for which an association does not hold (e.g., although heat accompanies the Sun’s rays, heat does not accompany the rays of the Moon).

“Idols of the Cave” refers to how people occupying different “caves,” or groups, differ in their scientific beliefs and practices. Here, Bacon described how scientists can become attached to ideas or practices “either because they fancy themselves the authors and inventors thereof, or because they have bestowed the greatest pains upon them and become most habituated to them.”

“Idols of the Marketplace” refers to the intellectual risks entailed in the use of language to conduct science. Bacon regarded this category of idol as the “most troublesome of all,” perhaps because one cannot escape using language and because the negative effects of this necessary practice can be so insidious. Included in this category is the tendency to assign names to things that do not exist, which encourages one to believe that they do exist. This happens whenever researchers use a single label (e.g., “breast cancer”) to refer to a collection of phenomena (“breast cancer” actually refers to many different pathophysiologic conditions). “Idols of the Theater,” or “Idols of the System,” refers to people’s tendency to cling to dogmatic systems of belief that portray a tidy and/or entertaining but ultimately inaccurate picture of nature.

Bacon, a contemporary of Galileo and Shakespeare, wrote Novum Organum at a time when many still believed that truths about the world were handed down by monarchs and ministers. He spoke for the burgeoning empirical sciences, encouraging readers to use the inductive method to throw off the shackles of authority. But if we are to realize his vision for a practice of science that frees people from the shackles of both authority and their own minds, it might be a good idea to update the idols to reflect the modern challenges threatening the scientific enterprise today.

The Idols of the Tribe, for example, need to expand to include the social psychological tendencies of group dynamics. The Idols of the Cave, which originally alluded to the conflicting interests of the scientist, must now emphasize the ubiquity and variety of financial and nonfinancial conflicts of interest attendant to the massive institutional and bureaucratic systems that have risen up around scientific activities. To the Idols of the Marketplace, meanwhile, we might add that the pressures within academic science to publish and win grants have exacerbated the use of trendy yet ill-defined terms. And finally, the Idols of the Theater might be updated to include the uncritical adherence to systems of ritualized rules intended to automate the inductive activities of scientists.

One year after the publication of Novum Organum, Bacon, who was seriously in debt, was accused of corruption, briefly jailed in the Tower of London, and barred from Parliament for life. It took several decades before his work began to receive wide praise, and in 1660 it inspired the creation of the Royal Society. A modern reader might be similarly inspired by Novum Organum’s subtlety of thought, commitment to understanding nature as it is, and excitement about the potential for science to be a liberating force for humankind.

About the author

The reviewer is at the Department of Population Health Sciences, Duke University School of Medicine, Durham, NC, USA.