Thomas a Kempis Quotes - Page 13
And when he is out of sight, quickly also he is out of mind.
'De Imitatione Christi' bk. 1, ch. 23, sect. 1
"Imitation of Christ", Book I, Chapter III. 6, as quoted in Hoyt's New Cyclopedia Of Practical Quotations, p. 313-14, 1922.
"Dictionary of Burning Words of Brilliant Writer" by Josiah Hotchkiss Gilbert, p. 372, 1895.