““I've come to suspect that whenever any ability is difficult to learn and rarely performed well, it's probably because contraries are called for - patting the head and rubbing the belly. Thus, good writing is hard because it means trying to be creative and critical; good teaching is hard because it means trying to be ally and adversary of students; good evaluation is hard because it means trying to be subjective and objective; good intelligence is rare because it means trying to be intuitive and logical.””
