Locke, Hume, and Mystery

Locke, Hume, and Mystery

Both Locke and Hume were mysterians. Locke stressed the limits of knowledge obtainable by the senses, this being the only basis for human knowledge; he thought that solidity, for example, has a nature we cannot know. Matter in general is a mystery for Locke. Hume focused on causation, but he too maintained that this aspect of the world transcends human knowledge. But curiously, neither philosopher extended this mysterian viewpoint to knowledge itself—why? They were quite confident about the nature of knowledge: they had a theory about it, namely empiricism. All knowledge derives from and is caused by experience: this is its nature, its essence, its reality. They never seem to have contemplated the possibility that knowledge might not be comprehensible by the human mind; in particular, they never wondered whether some types of knowledge (usually dubbed a priori) might have an unknown nature. They thought they knew exactly what knowledge intrinsically is, what explains it, what constitutes it. Why the inconsistency?

The answer isn’t at all obvious, but I have a hypothesis. The mysteries of matter were becoming clearer as the science of physics progressed, but the mysteries of mind had not yet become visible. Thus, consciousness itself was not perceived as mysterious—and knowledge is one of its attainments. More particularly, the role of the brain was not yet clear: brain science had not got off the ground—the nerve impulse was yet to be discovered. So, questions about mind and brain were not yet part of the intellectual landscape. If they were, our two philosophers would surely have wondered how the brain is capable of knowledge—how, indeed, experience arises from the brain. Then, mystery would have entered their calculations—mysteries of mind not just matter. They could be content with an empiricist theory knowledge because it never occurred to them that the mind might itself be a mystery—specifically, how knowledge is related to the physical world. They thought knowledge could not extend beyond experience because that was the only theory they were able to understand, neglecting the possibility that knowledge might work in ways they were incapable of understanding. Their inconsistency is therefore intelligible, if not defensible. In other words, our impressions of knowledge, like our impressions of solidity and causation, might not reveal the true of nature of what they are impressions of.