So long as a person lives in the world, he is kept midway between heaven and hell, and he is there in spiritual equilibrium. This is free will.
In order to know what free will is and what it is like, one needs to know its origin, It is chiefly by knowing its origin that one gets to know not only of its existence, but what it is like. It originates from the spiritual world, where a person's mind is kept by the Lord. A person's mind is his spirit, which lives after death; and his spirit is constantly in company with spirits in that world who are like himself, while his spirit is equally by means of the material body surrounding it in company with people in the natural world. The reason for a person's not knowing that as regards his mind he is surrounded by spirits, is that the spirits, in whose company he is in the spiritual world, think and talk spiritually, while so long as a person is in the material body, his spirit thinks and talks naturally. Spiritual thought and speech cannot be understood or heard by the natural man, and vice versa; this is why spirits cannot be seen either. However, when a person's spirit associates with spirits in their world, then he joins them in spiritual thought and speech, because his mind is inwardly spiritual, though outwardly natural. Therefore its interior permits him to communicate with those spirits, and its exterior with men. It is this communication which allows a person to perceive things, and to think about them analytically. Without this a man's thought would not go beyond or differ from an animal's; and if he were deprived of all contact with spirits, he would instantly die.
 But to render comprehensible how a person can be kept midway between heaven and hell, and by that means in spiritual equilibrium, I must explain briefly the origin of his free will. The spiritual world consists of heaven and hell; heaven there is overhead, hell is beneath the feet, yet not in the middle of the globe which men live on, but beneath the lands of the spiritual world. These too are of spiritual origin, and so not in space, though there is an appearance of space.
 Between heaven and hell there is a wide gap, which to those in it looks like a whole world. Into this gap there rise from hell exhalations of evil in boundless profusion, and, on the other hand, from heaven there flows in good, also in boundless profusion. This is the gap which Abraham described to the rich man in hell:
Between us and you a great gulf is fixed, to prevent those who want from passing across to you, and those there from passing across to us. Luke 16:26.
Everyone is as regards his spirit in the middle of this gap, for the sole purpose of allowing him to have free will.
 Because this gap is so huge and looks to those there like a great world, it is called the world of spirits. It is also full of spirits, for this is where everyone comes first after death, and is there prepared either for heaven or for hell. He is there in company with spirits, as he previously was with people in the world. There is no purgatory there; this is a fable invented by the Roman Catholics. I dealt in detail with that world in my book HEAVEN AND HELL (421-535), published in London in 1758.