On this slight thread of narrative, Johnson strung his thoughts with great felicity. The characters, by the different view which they entertain of life, are distinct and individual. The book is filled with pregnant and beautiful passages, which leave a deep impression on the reader. The words in which Imlac describes to the Prince and Princess the dangers of an unrestrained imagination, might, with equal propriety, find a place in a scientific treatise on the causes of insanity, and in a collection of beautiful literary extracts: To indulge the power of fiction, and send imagination out upon the wing, is often the sport of those who delight too much in silent speculation. When we are alone, we are not always busy; the labour of excogitation is too violent to last long; the ardour of inquiry will sometimes give way to idleness or satiety. He who has nothing external that can divert him, must find pleasure in his own thoughts, and must conceive himself what he is not; for who is pleased with what he is? He then expatiates in boundless futurity, and culls from all imaginable conditions that which for the present moment he should most desire, amuses his desires with impossible enjoyments, and confers upon his pride unattainable dominion. The mind dances from scene to scene, unites all pleasures in all combinations, and riots in delights which nature and fortune, with all their bounty, cannot bestow. In time, some particular train of ideas fixes the attention; all other intellectual gratifications are rejected; the mind, in weariness or leisure, recurs constantly to the favorite conception, and feasts on the luscious falsehood whenever she is offended with the bitterness of truth. By degrees, the reign of fancy is confirmed; she grows first imperious, and in time, despotic. Then fictions begin to operate as realities, false opinions fasten upon the mind, and life passes in dreams of rapture or of anguish.[191] The resemblance between Johnson's "Rasselas" and Voltaire's "Candide" is so marked, that had either author seen the other's work, he must have been suspected of imitation. But while both these great minds were writing at nearly the same time on the same theme of human misery, the lessons they taught differed in a manner which is strongly illustrative of the differences between the two men and their respective surroundings. French scepticism and distrust of divine power led Voltaire to impute human griefs to the incapacity of the Creator. But Johnson, writing "Rasselas" in an hour of sorrow, to obtain means to pay for his mother's funeral, taught that that happiness, which this world can not afford, should be sought in the prospect of another and a better.[192]