It is this incapability of experiencing life fully, and the innate desire to experience it, which makes the soul strive for spiritual attainment. What man does not know he thinks does not exist; in this is to be found the origin of materialism. But the tendency towards spiritual realization remains there as an innate desire which is consciously or unconsciously felt by every soul, whether spiritual or material. It is for this reason that even a material person has a silent craving in his heart to probe the depth of the very spiritual ideal which he disowns.