88. Since, then, without a perception of what correspondence is, it is impossible for anything to be known clearly about the spiritual world, or of its influx into the natural world, or even of what the spiritual is in relation to the natural, or anything with clearness about the spirit of man which is called the soul and of its operation into the body, or yet of the state of man after death, it is necessary, therefore, to explain what correspondence is and what is its nature. So also is the way prepared for what is to follow.