The archetype has no form of its own, but it acts as an "organizing principle" on the things we see or do. It works the way that instincts work in Freud's theory: At first, the baby just wants something to eat, without knowing what it wants. It has a rather indefinite yearning which, nevertheless, can be satisfied by some things and not by others. Later, with experience, the child begins to yearn for something more specific when it is hungry -- a bottle, a cookie, a broiled lobster, a slice of New York style pizza.
Here’s a simple example of a task that a concrete operations child couldn’t do, but which a formal operations teenager or adult could -- with a little time and effort. Consider this rule about a set of cards that have letters on one side and numbers on the other: “If a card has a vowel on one side, then it has an even number on the other side.” Take a look at the cards below and tell me, which cards do I need to turn over to tell if this rule is actually true? You’ll find the answer at the end of this chapter.