The further question arises, What is the origin of ideas? Men have been led into this erroneous belief in the reality of the material world by the fact that certain ideas are not subject to our will, while others are. Sensations are distinguished from the ideas of imagination, which we can excite and alter at pleasure, by their greater strength, liveliness, and distinctness, by their steadiness, regular order, and coherence, and by the fact that they arise without our aid and whether we will or no. Unless these ideas are self-originated they must have an external cause. This, however, can be nothing else than a willing, thinking Being; for without will it could not be active and act upon me, and without ideas of its own it could not communicate ideas to me. Because of the manifoldness and regularity of our sensations the Being which produces them must, further, possess infinite power and intelligence. The ideas of imagination are produced by ourselves, real perceptions are produced by God. The connected whole of divinely produced ideas we call nature, and the constant regularity in their succession, the laws of nature. The invariableness of the divine working and the purposive harmony of creation reveal the wisdom and goodness of the Almighty more clearly than "astonishing and exceptional events." When we hear a man speak we reason from this activity to his existence. How much less are we entitled to doubt the existence of God, who speaks to us in the thousandfold works of nature.