A far more satisfactory theory is that of _Rationalism_. It is a theory that admits that the human mind has some capacity for working upon the data presented to it by the sense organs. Man is no longer quite so helpless a creature as empiricism would make him. He is able to weigh and consider the facts that are presented to the mind. The method rationalism uses to arrive at truth is that of logical deduction, and the test of truth is that the steps in the process are logically sound. We may start from the data "All dogs are animals" and "Carlo is a dog," and arrive very simply at the conclusion "Carlo is an animal." The conclusion is correct because we have reasoned in accordance with the laws of logic, with the laws of valid thought. All logical reasoning is, of course, not so simple as the example given, but it may be stated generally that when there is no logical fallacy, a correct conclusion may be arrived at, provided, too--and herein lies the difficulty--provided that the premises are also true. These premises may be in themselves general statements--how is their truth established? They may be, and often are, the generalisations of the empirical sciences, and must then possess the same degree of uncertainty that these generalisations possess. Some philosophers have contended that certain general ideas are innate, but few would be found nowadays to accept such a contention. At other times mere definitions of terms may serve as premises. One might state as a premise the definition "A straight line is the shortest distance between two points," and the further statement that "AB is a straight line between A and B," and conclude that the line AB represents the shortest distance between two points A and B. In a manner similar to this Euclid built his whole mathematical system upon the basis of definitions and postulates, a system the complexity and thoroughness of which has caused all students of mathematics at one time or another to marvel and admire. But, of course, a definition is little more than assigning a definite term to a definite thing. It is when we begin to consider the premises that are necessary for arriving at the profound truths of the universe that we find the weakness of rationalism. How are we going to be provided with premises for this end? Shall we begin by saying "There is a God" or "There is no God"? How is the pure reasoning faculty to decide upon the premises in the matter of the great Beyond? We may weigh the arguments for and against a certain position, and we may think that the probability lies in a certain direction, but to decide finally and with certainty by mere cold logical reasoning is impossible. We may bring out into prominence through logical reasoning truths that were previously only implicit, but to arrive at absolute truth with regard to the invisible world, through intellect alone, has long been admitted to be an impossibility. The illusion of those who would believe that truth which