The thesis about psychometics and cognitive history, that they actually complement one another, and the remarks made about the brain imply a new approach to the theory of intelligence. A BIDS approach is needed: one that treats the brain (B), individual differences (ID), and social trends (S) as three distinct levels, each having equal integrity. The three are interrelated and each has the right to propose hypotheses about what ought to happen on another level. The core of a BIDS approach is that each of those levels has its own organizing concept and it is a mistake to impose the architectonic concept of one level on another. Despite static IQ, the developed world may enjoy a century of cognitive progress. IQ gains over time signal the evolution of minds that can be better educated. They provide no guarantee that the educating will be done.