Thus throughout antiquity, in spite of the evolution of ideas as to the future life, the persuasion always remained invincible that the spirits of the dead moved about among men. These disincarnate intelligences, which were, however, provided with light and swift bodies, did not let themselves be imprisoned in the tomb. They fluttered unceasingly around living beings, causing them to feel the effects of their presence. There is here, mingled with the primitive idea that a mysterious being, like it in appearance, has its place in the ground beside the buried corpse, the other and equally ancient idea that the soul is a breath exhaled by the dead at the moment when they expire. To breathe is the first act which marks the life of a newly born infant and to cease to breathe is the first sign which betokens the extinction of life. Primitive people therefore naturally thought that the principle which animated the body was a breath, which entered it at birth and left it at death. The very name which denotes the vivifying essence is in most languages witness to the general predominance of this conception. Ψυχή in Greek is connected with ψύχω, “to blow”; the Latin _animus_ or _anima_ corresponds to ἄνεμος, “wind,” and in the Semitic languages _nefeš̱_ and _ruaḥ_ have a similar meaning. At the moment in which man expired, his soul escaped through his mouth and floated in the ambient air. The Pythagoreans, when they taught that “the air is full of souls,”[139] were conforming to an old belief which is not Greek only but universal. When Virgil[140] shows us Dido’s sister, at the time of the queen’s suicide, receiving the last breath which floats on her dying lips, he is lending a Roman custom to the Carthaginians, the custom of the last kiss which, according to a widely held belief, could catch on its way the soul which was escaping into the atmosphere. This soul was often imagined as a bird in flight and we will see elsewhere the conclusions drawn from this naïve conception.[141] Here we wish merely to indicate how the idea of the aerial soul was combined with that of the spirit inhabiting the tomb. This shade or simulacrum of those who were no longer of this world, but who still existed, since they showed themselves to the living in their previous guise, was a body like the wind—intangible, invisible, save when it thickened like clouds or smoke. A multitude of these vaporous beings, innumerable as past generations, moved unceasingly on the earth’s surface, and, above all, roamed around the tombs, where they were retained by their attachment to their bodies. Whether, like the Greeks, men identified them with the “demons,” or, like the Romans, called them “Manes gods,” “_genii_” or “_lemures_,” or by other names, the unanimous opinion was that their power was superior to that of mankind and that they caused it to be felt by a constant intervention in the affairs of human society.