In 1958 Wechsler defined intelligence as the global and aggregate capacity of an individual to think rationally, to act purposefully and to deal effectively with his environment. The conceptual analysis is a philosophical task, and, typically, philosophers engage in the activity in a marked and obvious way. Intelligence testing began without an adequate conception of intelligence and continues without an adequate conception of education. Historically there have certainly been modifications and changes to the prevailing psychological accounts of intelligence, and psychologists themselves tend to see the changes as developments or improvements, so that it is assumed that we are dealing with progressively better accounts of the nature of intelligence. These general abilities are characteristics of intelligence, to be contrasted with related but distinct characteristics such as rote memory and sensory processes. This brings us directly to the substantive question of the value of standardized tests of intelligence.