The human spirit cannot climb upwards without taking successive steps. For every step upwards it needs the foundation of what has been constructed before--the past--which in, the comprehensive sense here employed, can have been laid only in a general civilization. All thinking originates only to a very small degree in personal experience. The largest part is based on the accumulated experiences of the past. The general level of civilization provides the individual, who in most cases is not consciously aware of the fact, with such an abundance of preliminary knowledge that with this equipment he can more easily take further steps on the road of progress. Adolf Hitler. Mein Kampf (Nation and Race)