The entries in this combined essay come from two very different traditions of thinking about human nature. One is the aphoristic tradition of moralists and writers, compact, sceptical and often funny. The other is the modern self-help literature, confident and practical and almost entirely untested. The precepts sit between them, and the most interesting of them hold two opposite attitudes at once.
Holding two attitudes at once
The precepts share a structure. Gramsci's Pessimism of the Intellect, Optimism of the Will and the Stockdale Paradox, from the prisoner of war who survived by confronting the facts while never losing faith in the outcome, both ask for clear-eyed assessment joined to determination. Reframing and the Act-As-If Principle take the practical route: change the interpretation, or change the behaviour, and let the feeling follow.
The aphorists
The moralists supply the group's most durable lines. La Rochefoucauld's maxim on others' misfortunes, that we all have strength enough to bear them, has lasted since the 1660s. Solzhenitsyn's Line, that the line between good and evil runs through every human heart, answers every theory that puts evil in other people. The Paradox of Hedonism and the Law of Reversed Effort observe that happiness and sleep both retreat when pursued directly. Simon's Ant proposes that the complexity of behaviour may lie in the environment rather than the creature, and Mel Brooks's definition of comedy makes La Rochefoucauld's point as a joke.
The self-help tradition
The largest part of the group comes from the success and self-help literature, from Napoleon Hill in the 1930s and Joseph Murphy in the 1960s to Tony Robbins and Eckhart Tolle. Thoughts Are Things, the Positive-Thinking Principle, Subconscious Programming and the Pain-Body share a view of the mind as something that can be reprogrammed by repetition, attention or belief.
The pattern the ledger finds across these entries is consistent. Almost every one has a researched relative that supports a narrower claim: Mental Rehearsal has motor-imagery research, the Meaning Principle has cognitive reappraisal, the Worry Futility Principle has the research on rumination. And almost every one states its claim more broadly than that research allows, with evidence drawn from people who followed the advice and succeeded.
Where it applies
The precepts are widely used in therapy, coaching and training: reframing is close to cognitive reappraisal, and act-as-if is close to behavioural activation. The aphorisms are useful as correctives, especially when a theory of human nature grows too flattering to its holder. The self-help principles reach more readers than any study in the evidence group, so knowing their researched relatives lets a reader keep the useful core and drop the rest.
Where it is argued over
Nearly all the self-help entries carry the contested flag. Their defenders argue that readers want motivation rather than proof, and that the advice rarely harms. Their critics reply that telling people their thoughts shape their circumstances implies that their circumstances are their fault, and that some of the advice, such as visualising outcomes, has been found in experiments to reduce effort. The Paradox of Choice, a popular book's claim rather than a self-help doctrine, sits here too: meta-analysis finds its average effect close to zero.
Why it is worth knowing
This group shows two ways of knowing about people. The aphorists compress long observation into a sentence and ask to be tested against the reader's experience. The self-help writers promise transformation and ask to be believed. Reading them side by side, and with the evidence essay's findings in mind, is a practical education in telling an insight from a sales pitch.
The entries behind this essay: Precept and Figure in Psychology & Behavior. Every subject has its essays on the essays page.