478. This spiritual equilibrium, which is free will, can be illustrated by instances of natural equilibrium. It is like the equilibrium of someone who is tied around the body or by the arms between two men of equal strength, one of whom pulls the person in the middle to the right, and the other to the left. Then the person in the middle can freely turn in one direction or the other, as if there were no force acting on him; and if he moves to the right, he pulls the man on the left violently towards himself, even to the point of making the man on the left fall to the ground. It would be the same if even a weak* man were tied between three men on the right and the same number of and just as strong men on the left; and likewise if he were tied between camels or horses.
 Spiritual equilibrium, which is free will, can be compared with a balance, in either scale of which are placed equal weights; if then a little is added to the scale on one side, the balancing beam above rocks. It is the same too with a lever, or with a large beam balanced on its fulcrum. Every single part inside the human body, such as the heart, the lungs, the stomach, the liver, the pancreas, the spleen, the intestines, and so on, is in such a state of equilibrium; and this is what allows each of them to perform its functions in the greatest tranquillity. It is the same with all muscles; if there were no such equilibrium in them, all action and reaction would cease, and the person would no longer be able to act as a person. Since then everything in the body is in such a state of equilibrium, and also everything in the brain is in like equilibrium, it follows that everything in the mind is too; and these things relate to the will and the understanding.
 Animals, birds, fish and insects also have freedom; but these are impelled by their bodily senses at the promptings of appetite and pleasure. A person would not be very different from them, if he were as free to act as he is free to think; he too would be impelled only by his bodily senses at the promptings of lust and pleasure. The case is different if he drinks in the spiritual teachings of the church and uses them to control his free will. The Lord leads him away from lusts and wicked pleasures and the innate longings he has for these; he strives after good, and turns his back on evil. He is then moved by the Lord nearer to the east and at the same time to the south in the spiritual world, and brought into heavenly freedom, which is true freedom.
* Reading imbecillis 'weak' for imbellis 'unwarlike'.