The commonsense theory is simple. If you or I wish to know something not yet known about the world, we have to open our eyes and look around. And we have to open our ears and listen to noises, and especially to those made by other people. Thus our various senses are our sources of knowledge — the sources of the entries into our minds.
I have often called this the bucket theory of the mind. …
In the philosophical world this theory is better known under the more dignified name of the tabula rasa theory of the mind: our mind is an empty slate upon which the senses engrave their messages. But the main point of the tabula rasa theory goes beyond the commonsense bucket theory: I mean its emphasis on the perfect emptiness of the mind at birth. For our discussion this is merely a minor point of discrepancy between the two theories, for it does not matter whether we are or are not born with some ‘innate ideas’ in our bucket — more perhaps in the case of intelligent children, fewer in the case of morons. The important thesis of the bucket theory is that we learn most, if not all, of what we do learn through the entry of experience into our sense openings; so that all knowledge consists of information received through our senses; that is, by experience.
In this form, this thoroughly mistaken theory is still very much alive. It still plays a part in theores of teaching, or in ‘information theory’, for example … . [60-1]