William Hazlitt described Francis Jeffrey as "eminently characteristic of the Spirit of the Age," given to "fair and free discussion ... open to argument and wit," at a time when "every question was tried upon its own ostensible merits, and there was no foul play." Jeffrey was, Hazlitt added, "a person in advance of the age," a man with "a great range of knowledge, an incessant activity of mind," one who "argues well for the future hopes of mankind" (The Spirit of the Age, 1825). In his Life of Lord Jeffrey (1852), Henry, Lord Cockburn, asserted, "It is impossible, on thus seeing the collected out-pourings of his mind, not to be struck by the variety of his matter .... there is scarcely a theme that he has not discussed, with all his fertility of view, and all his beauty of style."

According to Cockburn, "Totally devoid of ill nature, and utterly unconscious...