Expressed in practical terms, a normative theory, more properly called a policy, tells agents how they ought to act.

But evolutionary theory tells us that resources should be just as important to women, if not more so.

The theory also tells us that nothing can travel faster than light.

Vygotsky's theory tells us that adults are active agents in children's social development.

Doesn't your psychoanalytic theory tell you anything about that?

"But as good a theory as any," Rick told her.

This theory told the people that kings had the order of the gods to rule the country.

So both theory and experiment tell us that it is constant to the best of our abilities.

Right, economic theory tells us that production will continue in, in the short run providing average variable costs are covered.

The theory of evolution tells us that man and chimpanzees share a common ancestor.