The Gauls were very superstitious.[121] Persuaded that in the eyes of the gods the life of a man can only be redeemed by that of his fellow, they made a vow, in diseases and dangers, to immolate human beings by the ministry of the Druids. These sacrifices had even a public character.[122] They sometimes constructed human figures of osier of colossal magnitude, which they filled with living men; to these they set fire, and the victims perished in the flames. These victims were generally taken from among the criminals, as being more agreeable to the gods; but if there were no criminals to be had, the innocent themselves were sacrificed. Cæsar, who, according to the custom of his countrymen, gave to the divinities of foreign peoples the names of those of Rome, tells us that the Gauls honoured Mercury above all others. They raised statues to him, regarded him as the inventor of the arts, the guide of travellers, and the protector of commerce.[123] They also offered worship to divinities which the “Commentaries” assimilate to Apollo, Mars, Jupiter, and Minerva, without informing us of their Celtic names. From Lucan,[124] we learn the names of three Gaulish divinities, Teutates (in whom, no doubt, we must recognise the Mercury of the “Commentaries”), Hesus or Esus, and Taranis. Cæsar makes the remark that the Gauls had pretty much the same ideas with regard to their gods as other nations. Apollo cured the sick, Minerva taught the elements of the arts, Jupiter was the master of heaven, Mars the arbiter of war. Often, before fighting, they made a vow to consecrate to this god the spoils of the enemy, and, after the victory, they put to death all their prisoners. The rest of the booty was piled up in the consecrated places, and nobody would be so impious as to take anything away from it. The Gauls rendered also, as we learn from inscriptions and passages in different authors, worship to rivers, fountains, trees, and forests: they adored the Rhine as a god, and made a goddess of the Ardenne.[125] [Sidenote: Institutions]