We must combine the toughness of the serpent with the softness of the dove, a tough mind and a tender heart.
Source: In The Ultimate Success Quotations Library, 1997.
-- Martin Luther King, Jr, (Jan 15 1929-1968), US civil rights leader, clergyman; He eloquently led the non-violent Civil Rights movement, 1950-1968 and won the Nobel Prize, 1964.