Webster defines intelligence as follows.
The power or act of understanding; mental acuteness or sagacity; the power of meeting any situation, esp. a novel situation, successfully by proper behavior adjustments; the ability to apprehend the interrelationships of presented facts in such a way as to guide action towards a desired goal.
Any of these definitions may be applied to second-level thinking. Third-level thinking enhances and continues this process; it amplifies “mental acuteness or sagacity.” Thus, thinking and intelligence amount to much the same thing. Chapter Two investigates this connection a little more fully by discussing the mental gymnastics of problem solving.
- Webster’s New Collegiate Dictionary, John P. Bethal, General Editor (Springfield, Mass.: G. & C. Merriman Co., 1959).