Intelligence is a term commonly applied to the capacity of humans (and sometimes that of other higher mammals) to accomplish a wide range of mental tasks, including comprehension, analysis, abstraction, and prediction among others. It is named as a key factor in learning and success in the academic, occupational, personal, and social domains. Parts of Plato’s great work The Republic can be read as foreshadowing the modern interest in intelligence as an account for success. He conceived the citizens of his utopia as having different capacities, and only a few individuals—he included both men and women in this group—were able (among other things) to engage in the deep, abstract thought needed to excel in the study of mathematics and metaphysics, which would equip them to ...