16. Just as science, properly speaking, has for object the study of the laws of material principles, the special object of Spiritism is the knowledge of the laws of spiritual principles. As this latter class of principles is one of the forces of nature, as it acts incessantly and reciprocally upon the material principles, the result of it is that knowledge of one cannot be complete without knowledge of the other; that separated, they are incomplete; that science without Spiritism finds itself utterly powerless to explain certain phenomena by laws of matter alone; - while Spiritism without science would lack support and control. The study of the material laws should precede that of the spirituality, as it is matter that first touches the senses. If Spiritism had appeared before the scientific discoveries, it would have been rejected, as is the case with all that comes before its time.