“Before we sense anything, then, the mind is as bare and empty as a blackboard before the teacher arrives in the classroom. Locke also compared the mind to an unfurnished room. But then we begin to sense things. We see the world around us, we smell, taste, feel, and hear. And nobody does this more intensely than infants. In this way what Locke called simple ideas of sense arise. But the mind does not just passively receive information from outside it. Some activity happens in the mind as well. The single sense ideas are worked on by thinking, reasoning, believing, and doubting, thus giving rise to what he calls reflection. So he distinguished between ‘sensation’ and ‘reflection.’ The mind is not merely a passive receiver. It classifies and processes all sensations as they come streaming in. And this is just where one must be on guard.”