Let us specify that the possible gaps in the human mind are due, not to fortuitous causes, but to the very conditions of the "dark age", the kali-yuga, which has as an effect − among other modes of decadence − a progressive weakening of pure intellection and of the ascending tendencies of soul; whence the necessity of the religious revelations, and whence also the problematical phenomenon of gratuitous and divergent philosophies.