Their cardinal doctrine was that souls did not perish, but that after death they passed from one person to another; and this they regarded as a supreme incentive to valour, since, with the prospect of immortality, the fear of death counted for nothing.

They carried on, moreover, many discussions about the stars and their motion, the greatness of the universe and the lands, the nature of things, the strength and power of the immortal gods, and communicated their knowledge to their pupils.

In another passage Caesar says that the Gauls as a people were extremely devoted to religious ideas and practices.

Men who were seriously ill, who were engaged in war, or who stood in any peril, offered, or promised to offer, human sacrifices, and made use of the Druids as their agents for such sacrifices.

Their theory was, that the immortal gods could not be appeased unless a human life were given for a human life.