In his book on Marcus Aurelius, Renan[211] compares his philosophy of resignation with the Nirvâna of the Buddhists. “Like Jesus, Çakya-Mouni, Socrates, Francis of Assisi, and three or four other wise men, Marcus Aurelius was victor over death. He could laugh at it, because it had no longer any meaning for him.” But, just as the theories of Buddha became transformed into a religion which promised the immortality of the soul, and as Nirvâna gave way to the Paradise of the Easterns with its delights, so the sceptical resignation of ancient philosophy was vanquished by Christianity with its promises of a future life and immortality. Thus, in the course of the centuries, philosophy has been drowned in the floods of sentiment and of religious notions, and it has been a labour of Sisyphus to restore reason to humanity. There is the less need to follow the stages of this resurrection, as, in the end, they come to little. For long, philosophical systems set themselves the task of supporting the dogmas of religion by arguments independent of divine revelation. The gods were replaced by philosophy or by matter, and an effort was made to solve the eternal and disquieting problem of death by proving the immortality of the soul. The philosophers of the early renaissance of human thought accepted the chief religious dogmas as established truth. Plotin regarded the immortality of the soul as a self-evident truth that required no proof. He argued against a resurrection of the body, but accepted the transmigration of souls. Although Spinoza had given up the conception of the immortality of the soul in the ordinary sense, he accepted the Aristotelian idea that “the human spirit could not be destroyed absolutely with the body, but left some eternal remnant.” Death, in his view, was a kind of eternal life, a merging with the absolute, a return to the immortal and universal substance. Philosophers have exhausted themselves in the study of the foundations of human knowledge with the sole object of demonstrating the truth of religious dogmas. In spite of his scepticism, Kant tried to prove the genuineness of human knowledge, and to found on that a conviction of the future life and of the existence of God. Fichte set himself the same task, but he was forced to recognise that “immortality cannot be deduced from natural phenomena,” and that it “is supernatural.” “Although we cannot understand the possibility of eternal life, it still may be possible, for it transcends human knowledge.” Hegel reached a pantheistic conclusion and believed in the human soul being re-absorbed by the absolute.