Observe a man’s actions; scrutinize his motives; take note of the things that give him pleasure. How, then, can he hide from you what he really is?

Confucius (c. 551- c. 479 BC) Chinese philosopher, sage, politician [孔夫子 (Kǒng Fūzǐ, K'ung Fu-tzu, K'ung Fu Tse), 孔子 (Kǒngzǐ, Chungni), 孔丘 (Kǒng Qiū, K'ung Ch'iu)]

The Analects [Lun Yü], 2.10 (6th C. BC) [ed. Lao-Tse] [tr. Giles (1907)]
    (Source)

Alt. trans.:

• "See what a man does. Mark his motives. Examine in what things he rests. How can a man conceal his character?" [tr. Legge (1930)]
• "Observe [shi] what a man does. Look into [guan] what he has done [you]. Consider [cha] where he feels at home. How then can he hide his character?" [tr. Chin (2014)]
• "See what a man does; contemplate the path he has traversed; examine what he is at ease with. How, then, can he conceal himself?" [tr. Huang (1997)]