I. All things in the universe have relation to good and truth, and to the conjunction of both, in order that they may be anything; consequently to love and faith, and their conjunction. II. With man there is will and understanding, and the will is the receptacle of good, and the understanding the receptacle of truth, and all things with man have relation to those two, and to their conjunction, as all things relate to good and truth, and their conjunction. III. There is an internal man and an external, and they are distinct one from the other like heaven and the world, and nevertheless that they ought to make one, in order that man may be truly man. IV. The light of heaven is that in which the internal man is, and the light of the world that in which the external is; and the light of heaven is the Divine truth itself, from which is all intelligence. V. There is a correspondence between the things which are in the internal, and those which are in the external man; and consequently they appear in each under a different form, so that they can only be discerned by the science of correspondences. Unless these and many other things are known, it is impossible to form any ideas concerning spiritual and celestial things, but such as are incongruous; and thus the scientifics and knowledges, which are of the external man, without these universals, can be of little service to the rational man for understanding and growth. Hence it appears, how necessary scientifics are. Concerning those universals, much is said in the Arcana Coelestia.