During my subsequent years of study, however, I found myself no nearer an answer to the problem that haunted me. All that I experienced, in scientific work as in life generally, merely gave it an even sharper edge. Everywhere I saw an abyss widening between human knowing and human action. How often was I not bitterly disillusioned by the behaviour of men for whose ability to think through the most complicated scientific questions I had the utmost admiration!