Of course, the ‘potentialities’ are not constant or unalterable. The teacher should not content himself with the notion that the children’s varied performances-in mathematics say-are the reflection of their ability levels. Abilities are not something foreordained once and for all: they are
Formed and developed through instruction, practice and mastery of an activity. Therefore we speak
Of the necessity of forming, developing, cultivating and improving children’s abilities, and we cannot
Predict exactly how far this development may go.