Science, of course, is predicated on optimism -- the faith that the human lot can be improved through knowledge. What Dr. Monygham found in his interior wanderings was a doctrine of cynical pessimism, which indeed contains "nothing for science."

The "twilight" that attaches itself to Monygham's "personality" (and which comes from the "interior") subtly emphasizes the symbolism of light as idea, and half-light in particular as a strong dream-ideal. Conrad more than once insists that Monygham's cynicism, though superficially anti-ideals, is itself an dream-ideal. See .