Connection of this doctrine with the theory of conservation and correlation of force.—­Parallel between the origin and destiny of the body and the soul.—­The necessity of founding human on comparative psychology.

Averroism, which is based on these facts, is brought into Christendom through Spain and Sicily.

History of the repression of Averroism.—­Revolt of Islam against it.—­Antagonism of the Jewish synagogues.—­Its destruction undertaken by the papacy.—­Institution of the Inquisition in Spain.—­Frightful persecutions and their results.—­Expulsion of the Jews and Moors.—­Overthrow of Averroism in Europe.—­Decisive action of the late Vatican Council.

The pagan Greeks and Romans believed that the spirit of man resembles his bodily form, varying its appearance with his variations, and growing with his growth.  Heroes, to whom it had been permitted to descend into Hades, had therefore without difficulty recognized their former friends.  Not only had the corporeal aspect been retained, but even the customary raiment.

The soul.  The primitive Christians, whose conceptions of a future life and of heaven and hell, the abodes of the blessed and the sinful, were far more vivid than those of their pagan predecessors, accepted and intensified these ancient ideas.  They did not doubt that in the world to come they should meet their friends, and hold converse with them, as they had done here upon earth —­an expectation that gives consolation to the human heart, reconciling it to the most sorrowful bereavements, and restoring to it its dead.

In the uncertainty as to what becomes of the soul in the interval between its separation from the body and the judgment-day, many different opinions were held.  Some thought that it hovered over the grave, some that it wandered disconsolate through the air.  In the popular belief, St. Peter sat as a door-keeper at the gate of heaven.  To him it had been given to bind or to loose.  He admitted or excluded the Spirits of men at his pleasure.  Many persons, however, were disposed to deny him this power, since his decisions would be anticipatory of the judgment-day, which would thus be rendered needless.  After the time of Gregory the Great, the doctrine of purgatory met with general acceptance.  A resting-place was provided for departed spirits.

That the spirits of the dead occasionally revisit the living, or haunt their former abodes, has been in all ages, in all European countries, a fixed belief, not confined to rustics, but participated in by the intelligent.  A pleasing terror gathers round the winter’s-evening fireside at the stories of apparitions, goblins, ghosts.  In the old times the Romans had their lares, or spirits of those who had led virtuous lives; their larvae or lemures, the spirits of the wicked; their manes, the spirits of those of whom the merits were doubtful.  If human testimony on such subjects can be of any value, there is a body of evidence reaching from the remotest ages to the present time, as extensive and unimpeachable as is to be found in support of any thing whatever, that these shades of the dead congregate near tombstones, or take up their secret abode in the gloomy chambers of dilapidated castles, or walk by moonlight in moody solitude.