From Bretherton, I. (1992). The origins of attachment theory: John Bowlby and Mary Ainsworth. Developmental Psychology, 28, 759:
"In his last work, a biography of Charles Darwin, Bowlby may have been talking about himself when he said of Darwin:
Since causes are never manifest, the only way of proceeding is to propose a plausible theory and then test its explanatory powers against further evidence, and in comparison with the power of rival theories..,. Since most theories prove to be untenable, advancing them is a hazardous business and requires courage, a courage Darwin never lacked. (Bowlby, 1991, p. 412)"
It takes courage to be curious, question, imagine, challenge, offer up an alternative explanation, and test it, knowing all the while that you may be wrong, publicly, or that you may be on target and still viewed as wrong, publicly.