Dickinson had a remarkable mind. He was a very careful investigator and thinker. A
very logical thinker. When he was teaching me x-ray crystallography, he also taught me to
ask at each stage in the argument: what assumptions are being made? How reliable is the
conclusion that you draw? What chance is there that one of the assumptions you have made
is not correct? "You should recognize," he said to me, "that there is in
almost every investigation a lack of complete rigor. You should understand just how
reliable the arguments are that you are presenting."