The title is influenced by a verse in the Bible from the Book of Proverbs, chapter 23, verse 7: “As a man thinketh in his heart, so is he.” The full passage, taken from the King James Version, is as follows:
Eat thou not the bread of him that hath an evil eye, neither desire thou his dainty meats:
For as he thinketh in his heart, so is he:
Eat and drink, saith he to thee; but his heart is not with thee.
The morsel which thou hast eaten shalt thou vomit up, and lose thy sweet words.
While the passage suggests that one should consider the true motivations of a person who is being uncharacteristically generous before accepting his generosity, the title and content of Allen's work refer to the reader himself.
"A man is literally what he thinks, his character being the complete sum of all his thoughts."
"Cherish your visions. Cherish your ideals. Cherish the music that stirs in your heart, the beauty that forms in your mind, the loveliness that drapes your purest thoughts, for out of them will grow all delightful conditions, all heavenly environment, of these, if you but remain true to them your world will at last be built."
"The soul attracts that which it secretly harbors, that which it loves, and also that which it fears. It reaches the height of its cherished aspirations. It falls to the level of its unchastened desires - and circumstances are the means by which the soul receives its own."
"Men are anxious to improve their circumstances, but are unwilling to improve themselves, they therefore remain bound."
As the physically weak man can make himself strong by careful and patient training, so the man of weak thoughts, can make them strong by exercising himself in right thinking."
"Every man is where he is by the law of his being; the thoughts which he has built into his character have brought him there, and in the arrangement of his life there is no element of chance, but all is the result of a law which cannot err."
“The thoughtless, the ignorant, and indolent, seeing only the apparent effects of things and not the things themselves, talk of law, of fortune, and chance. Seeing a man grow rich, they say, "How lucky is!" Observing another become intellectual they exclaim, "How highly favored he is!" And noting the saintly character and wide influence of another, they remark, "How chance aids him at every turn!" They don't see the trials and failures and the struggles which these men have voluntarily encountered in order to gain their experience; have no knowledge of the sacrifices they have made, of the undaunted efforts they have put forth, of the faith they have exercised, that they might overcome the apparently insurmountable, and realize the vision of their heart. They do not know the darkness and the heart aches; they only see the light and the Joy, and they call it “luck”; do not see the longing arduous journey, but only behold the pleasant goal, and call it "good fortune"; do not understand the process, but only perceive the result, and call it “chance”.” “The circumstances which a man encounters with suffering are the result of his own mental inharmony.”
In Francis Ford Coppola's film adaptation of the S.E. Hinton novel Rumble Fish, Motorcycle Boy is seen reading this book by Rusty James's bedside when James is recuperating from his fight with Biff Wilcox early in the film.