The influence of the rising natural science led to the opposite answer to the question as to whether the basis of our responsibility is spiritual freedom or universal causation. Hobbes and Spinoza became the champions of universal causation, presenting their answer to the question with a clearness and incisiveness imposing even to-day. Leibniz too adopted it, but took care not to offend those holding to the other view. It has never been lost again from psychology. These men teach that the phenomena of the mental life are in one respect exactly like those of external nature, with which they are indeed closely connected: at any moment they are definitely fixed through their causes, and cannot be otherwise than as we actually find them. Freedom of action in the sense of causelessness is an empty concept. It follows from this that one can properly mean by freedom of action only that there is no compulsion from without, that the action of a thing or being is determined only by its own nature, its own indwelling properties. We say of water that it flows along freely if it is not checked by rocks or dams; or of a horse, that it runs about freely, if it is not tied up or locked in a stall. We can in this sense call the good deeds of a person or his living together with other people his own free action, if it springs from his own deliberations and desires and is not coerced by force or threats. Nevertheless all these manifestations, the flowing, the running about, and also the good actions, are alike the regular effects of definite causes.
What constantly prevents men from recognizing this causality and leads them to a belief in a misinterpreted freedom, is solely their ignorance. Out of the multitude of motives for their actions they see, in most cases, only a single one; and if the action which takes place does not correspond with it, they are convinced that the decision occurred without cause. “A top,” says Hobbes, “which is spun by boys and runs about, first towards one wall then towards another, would think, if it perceived its own motion, that it moved about by the exercise of its own will, unless it happened to know what was spinning it.” In the same way people apply for a job or try to make a bargain and think that they do this by their own wills; they do not see the whips by which their wills are driven. In order to understand correctly the thoughts and impulses of man, we must treat them just as we treat material bodies, or as we treat the lines and points of mathematics. The pretended dangers of such a conception of things disappear, as soon as we face them without prejudice and try to understand them. The conception may be misused, especially by people of immature mind, but “for whatever purpose truth may be used, true still remains true,” and the question is not, “what is fit to be preached, but what is true.”