The Grammar of Science, Karl Pearson
Chapter IV: Cause and Effect
1. Cause is scientifically used to denote an antecedent stage in routine of perceptions. In this sense force as a cause is meaningless. First cause is only a limit, a permanent or temporary, to knowledge. No instance, certainly not will, occurs in our experience of an arbitrary first cause in the popular sense of the word.
2. There is no inherent necessity in the routine of perceptions, but the permanent existence of rational beings necessitates a routine of perceptions with the cessation of routine ceases the possibility of a thinking being. The only necessity we are acquainted with exists in the sphere of conceptions; possibly routine in perceptions is due to the constitution of the perceptive faculty.
3. Proof in the field of perceptions is the demonstration of overwhelming probability. Logically we ought to use the word know only of conceptions, and reserve the word believe for perceptions. “I know that the angle at the circumference on any diameter of a circle is right,” but “ I believe that the sun will rise to-morrow.” The proof that for no finite future a breach of routine will occur depends upon the solid experience that where we are ignorant, there statistically all constitutions of the unknown are found to be equally probable.