A. G. K. L'Estrange, History of English Humour, Vol…
“ When the cause of our laughter—be it mind, matter, or imaginary circumstance—is merely regarded as something incongruous and amusing, we name it the ludicrous, and a man is called ludicrous as faulty or contemptible. But when the cause of it is viewed as something more than this, as coming from some conscious power or tendency within us—a valuable gift and an element in our mental constitution—we call it humour, a term applied only to human beings and their productions; and a man is called humorous as worthy of commendation. ”
