What does it take to live a good life, to flourish, to be happy? The art-science of happiness has been contemplated since the dawn of recorded thought, and yet no agreement seems to have been reached: For Albert Camus, it was about escaping our self-imposed prisons; for Alan Watts, about living with presence; some have pointed to learned optimism as the key, while others have scoffed at optimism and advocated for embracing uncertainty instead. But if there is one immutable truth about happiness, it’s that it is never a static thing — not a permanent state, but a constantly evolving experience of being, one that George Eliot believed had to be learned, transformed in each new moment and sculpted by the passage of time.

One of history’s most beautiful and crystally aware meditations on happiness, specifically in terms of how it illustrates the schism between the experiencing self and the remembering self, comes from The Diary of a Man of Fifty (public library; free download) — one of the finest, most timelessly resonant notable diaries of all time — by literary legend Henry James (April 13, 1843–February 28, 1916).

In early April of 1874, approaching his fifty-first birthday, James returned to Florence, where he had visited in his youth. His diary entry from April 5th bespeaks the odd elasticity of time in our conscious memory, with all its propensity for modification:

They told me I should find Italy greatly changed; and in seven-and-twenty years there is room for changes. But to me everything is so perfectly the same that I seem to be living my youth over again; all the forgotten impressions of that enchanting time come back to me. At the moment they were powerful enough; but they afterwards faded away. What in the world became of them? Whatever becomes of such things, in the long intervals of consciousness? Where do they hide themselves away? In what unvisited cupboards and crannies of our being do they preserve themselves? They are like the lines of a letter written in sympathetic ink; hold the letter to the fire for a while and the grateful warmth brings out the invisible words.

James adds a simple yet powerful definition of happiness — or, at the very least, of existential satisfaction — with equal parts poignancy and humor:

I have led too serious a life; but that perhaps, after all, preserves one’s youth. At all events, I have travelled too far, I have worked too hard, I have lived in brutal climates and associated with tiresome people. When a man has reached his fifty-second year without being, materially, the worse for wear — when he has fair health, a fair fortune, a tidy conscience and a complete exemption from embarrassing relatives — I suppose he is bound, in delicacy, to write himself happy.

The Diary of a Man of Fifty is an indispensable trove of wisdom and is available as a free download.