distinguish the nature of the evidence in the two cases. You may still sometimes hear arguments amounting to this: since I believe in Calcutta on authority, am I not entitled to believe in the Devil on authority?
Now people at all times have been commanded or expected or invited to accept on authority alone—the authority, for instance, of public opinion, or a Church, or a sacred book—doctrines which are not proved or are not capable of proof. Most beliefs about nature and man, which were not founded on scientific observation, have served directly or indirectly religious and social interests, and hence they have been protected by force against the criticisms of persons who have the inconvenient habit of using their reason. Nobody minds if his neighbour disbelieves a demonstrable fact. If a sceptic denies that Napoleon existed, or that water is composed of oxygen and hydrogen, he causes amusement or ridicule. But if he denies doctrines which cannot be demonstrated, such as the existence of a personal God or the immortality of the soul, he incurs serious disapprobation and at one time he might have been put to death. Our mediæval friend would have only been called a fool if he doubted the existence of Constantinople, but if he had questioned the significance of comets he
