This paper provides a critical and detailed study of what researchers in the fields of contemporary cognition and neuroscience have revealed about the blurred boundary between perception and cognition. We set out the arguments with a view to what researchers and teachers should now consider regarding the subtleties of their interrelationship in children's learning, and how individuals may be better helped to grasp difficult ideas. The analysis spotlights children's cosmologies in science education--their acquisition of ideas in basic astronomy concerning the Earth, Sun, Moon and so forth--and we use illustrative examples drawn from our own research to emphasise the implications of what "perceiving" and "cognising" actually mean. The role of carefully exercised Socratic dialogue as part of a constructivist approach to learning lies at the core of our deliberations.