The History of Rasselas, Prince of Abyssinia, Samuel Johnson's "philosophical romance," concerns the desire of the eponymous protagonist to discover whether it's possible for mankind to attain happiness. Although he himself has lived a life of unbroken serenity amidst boundless luxuries in a beautiful setting, both aptly and ironically named Happy Valley, the twenty-six-year-old prince has become sated with this existence and is anything but a happy man.

After numerous failed efforts to interest himself in local affairs, Rasselas seeks to escape from Happy Valley but finds every path has been blocked. He meets Imlac, a visiting sage, who describes to the prince the pain and oppression of a world yet unseen by him, with the tale of his own vicissitudes therein. Listening to this narrative makes the prince even more eager to see the outer world himself and, with the wise man's guidance, he digs a tunnel through the mountains to escape. The prince's favorite sister, Nekayah, who is as dissatisfied as her brother, joins them on their journey. She is accompanied by her maidservant, Pekuah.

As they travel through the world, the initial astonishment of the royal siblings fades as Imlac instructs them in the endlessly varied manners of the human race. Rasselas continues in his search to solve the mystery of happiness but finds it as frustratingly elusive as he had in Happy Valley. Neither the pursuit of sensual pleasures, the possession of wealth, nor the attainment of learning seem to guarantee his intangible objective. Nekayah, who has spent much of her time observing domestic life, also is saddened to find a status quo of discontent.

At Imlac's suggestion, Rasselas and Nekayah join him in visiting a pyramid, while leaving the claustrophobic Pekuah to rest in their tent. After reflecting on the folly of the royal vanity that built such a monument, the trio emerges into the light to find that Pekuah has been seized by Arab horsemen. Rasselas is eager to give chase, but Imlac reminds him that they are no match for Pekuah's captors. Nekayah is grief-stricken.

The search for Pekuah continues as Nekayah languishes, but after seven months, the princess is overjoyed when they learn that her maid is alive. She is being held by an Arab chief who demands a ransom for her return, which they immediately pay.

Order restored, the travelers contemplate the future. When Rasselas declares to Imlac that he is considering a solitary life devoted to learning and literary pursuits, the sage tells him about an erudite astronomer friend—seemingly perfect in every way—who one day quietly revealed to him his godlike control of the universe and his intention to pass this power on to Imlac. Such madness, he warns, is the potential danger of a solitary life. Fascinated by this astronomer, the women demand that Imlac arrange a visit. Over a period of months in their company, the man gradually regains his sanity.

But, what does Rasselas ultimately determine to be the source of human happiness? According to Nekayah, the “state of life” is that no one is happy except for in the possibility of change or something new. As humans, we are continually navigating and wishing for change in our lives. This is hopeful overall because this attitude means that the “world isn’t exhausted yet.” In other words, there will always be possibility and newness in the world around us: we just have to look.