Today we began by considering two ways of understanding Locke’s ideas. One model, which we found in Nicolas Malebranche, says that ideas are mental entities. The other, from Antoine Arnauld, proposes that ideas are the act of perception considered from within. Locke is not clear about his own position. Sometimes he looks like Arnauld, sometimes like Malebranche.
Locke rejects the possibility of innate ideas. Since ideas are obviously not available to us at birth, he argues that any account of innate ideas will require innate ideas to become clear in the mind just as they seem to be learned – and so there is no reason to think they are innate.
Locke thinks that a human person is always either thinking or perceiving. There are always ideas in a person’s mind. That means that in a dreamless sleep, though the body is present, the whole person is absent. Locke illustrates this with a science-fiction-y thought experiment. Another person could share your body while you sleep. Unlikely, yes, but perfectly possible.
Since there are no innate ideas, the mind is empty at birth. Ideas flow in through sensation and reflection – and that’s it. Ideas function for Locke as atoms of thought. Simple ideas are the building blocks of other ideas. They cannot be made or destroyed, only acquired through experience. We build these simple ideas up into complex ideas. We’ll hear more about complex ideas in the weeks to come.