Note 1: (Dr. Johnson's celebrated judgment) According to the Chapman edition of Mansfield Park, this is a reference to Samual Johnson's work "The History of Rasselas, Prince of Abissinia", in which he writes:
"I have met, said the princess, with many who live single for that reason; but I never found that their prudence ought to raise envy. They dream away their time without friendship, without fondness, and are driven to rid themselves of the day, for which they have no use, by childish amusements, or vicious delights. They act as beings under the constant sense of some known inferiority, that fills their minds with rancour, and their tongues with censure. They are peevish at home, and malevolent abroad; and, as the out-laws of human nature, make it their business and their pleasure to disturb that society which debars them from its privileges. To live without feeling or exciting sympathy, to be fortunate without adding to the felicity of others, or afflicted without tasting the balm of pity, is a state more gloomy than solitude: it is not retreat but exclusion from mankind. Marriage has many pains, but celibacy has no pleasures."
The entire text can be read here: Rasselas.