One must stop to think, to analyze the situation, to figure out what went wrong and what to do about it. Present difficulties are an opportunity for thought. One examines the past. One faces the facts of the present situation. One imagines a way out of the present situation, a course of action leading to a favorable outcome.
Intelligence is reflection upon what is needed to direct the conditions of the present situation.
Intelligence increases with each new resolution and intervention. It is a learned behavior. The thrust of individual character and energy, the direction of activity. What one wants to do and what one is accustomed to doing. Education must gear common content to individual interest, so that interest may be broadened and enriched.