Let me quote the book:
"Because Rationals value the strategic intellect so highly, the tend to take as their idol the technological wizard, especially the scientific genius. After all, a wizard is the ultimate scientist, with what seems an almost magical power over nature, and in single-minded pursuit of the four aims of science: the prediction and control of events, and the understanding and explanation of their contexts."
Yeah, that. Granted, a rational person might not be strictly scientific, but only "scientific" in the humblest of senses: observation. See, that's what science is at its base point. It's looking, observing, and making conclusions based on what one has observed. It is not a tall man in a white coat staring at beakers of colored liquid. It's not a giant jellyfish of knowledge that will punish you for saying or doing something "unscientific". Human understanding is limited, and thus we must with the most childlike, humble observation go forward in science, allowing our old notions to be wrong if experience shows that to be the case. So, a child playing with a faucet is science, because the child is observing and coming to conclusions about a small piece of the world: a sink where he is taking a bath.
But beyond that, Istari!
