The Happiness Hypothesis: Finding Modern Truth in Ancient Wisdom is a 2006 book written by American social psychologist Jonathan Haidt.

In it, Haidt poses several "Great Ideas" on happiness espoused by thinkers of the past—such as Plato, Buddha and Jesus—and examines them in the light of contemporary psychological research, extracting from them any lessons that still apply to our modern lives.

This leads in the fourth chapter to a description of the tendency that people have of seeing faults in others more readily than in themselves, which by simply realizing we might go to some length to rectify and thus come closer to living by the Golden Rule.

He identifies ways of improving happiness by altering these, including spending money well, and argues that the Western emphasis on action and striving is not without merit.

The ancients, according to Haidt, had a sophisticated psychological understanding of virtue, using maxims, fables and role-models to train "the elephant," the automatic responses of the individual.

Though the beginnings of Western virtue lie in Homer, Aesop and the Old Testament, the modern understanding of it has much to do with the arguments of Kant (the categorical imperative) and Bentham (utilitarianism).

To address the question of how a common morality can be forged in a diverse society, Haidt turns to positive psychology, specifically to Seligman and Peterson's work on virtues and strengths.

[3] Using the metaphor of Flatland, Haidt argues that the perception of sacredness and divinity are two basic features of the human mind; the emotions of disgust, moral elevation, and awe tell us about this dimension, but not everybody listens.

[4] The work of William James and of Abraham Maslow (on "peak experiences") shows ways in which this dimension is also relevant to the non-religious.

A study by Mihaly Csikszentmihalyi, Howard Gardner and William Damon[5] established the concept of "vital engagement" which characterises work with the most sense of purpose.

Daniel Nettle, reviewing the book in Nature, accepted its central premise of a "striking similarity between the advice of the ancients on how to live, and the thoughts of modern psychologists on how to have a healthy mind."

"[7] Christopher Hart writing in The Times described the book as "humane, witty and comforting...brilliantly synthesising ancient cultural insights with modern psychology.