Giving importance to what we think because we thought it, taking our own selves not only (to quote the Greek philosopher) as the measure of all things but as their norm or standard, we create in ourselves, if not an interpretation, at least a criticism of the universe, which we don't even know and therefore cannot criticize. The giddiest, most weak-minded of us then promote that criticism to an interpretation that's superimposed, like a hallucination; induced rather than deduced. It's a hallucination in the strict sense, being an illusion based on something only dimly seen.

The Education of the Stoic