537. But something about that equilibrium shall first be told. It is acknowledged that when two things mutually act against each other, and as much as one reacts and resists the other acts and impels, since there is equal power on either side, neither has any effect, and both can then be acted upon freely by a third. For when the force of the two is neutralized by equal opposition the force of a third has full effect, and acts as easily as if there were no opposition. [2] Such is the equilibrium between heaven and hell. Yet it is not an equilibrium like that between two bodily combatants whose strength is equal; but it is a spiritual equilibrium, that is, an equilibrium of falsity against truth and of evil against good. From hell falsity from evil continually exhales, and from heaven truth from good. It is this spiritual equilibrium that causes man to think and will in freedom; for whatever a man thinks and wills has reference either to evil and falsity therefrom or to good and truth therefrom. [3] Therefore when he is in that equilibrium he is in freedom either to admit or accept evil and its falsity from hell or to admit or accept good and its truth from heaven. Every man is held in this equilibrium by the Lord, because the Lord rules both heaven and hell. But why man is held in this freedom by such an equilibrium, and why evil and falsity are not taken away from him and good and truth implanted in him by Divine power will be told hereafter in its own chapter.