The Limits of Knowledge

Superstition and opinion are burdens; cast them off.

There are two kinds of people: those who know when they don't know and those who don't know when they don't know. From Plato to the moderns, philosophers make a meal of the topic of knowledge, but there is much that can be said without indulging in arcane language.

The first thing to say about knowledge is that it always contains some element of uncertai…