II. 3. 7
(Armstrong Selection and Translation from the Enneads)
But if these heavenly powers give signs of things to come — as we maintain that many other things also do — what might the cause be? How does the order work? There would be no signifying if particular things did not happen according to some order. Let us suppose that the stars are like characters always being written on the heavens, or written once for all and moving as they perform other tasks as well as their principal one: and let us assume that their significance results from this, just as because of the one principle in a single living being, by studying one member we can learn something else about a different one. For instance, we can come to conclusions about someone’s character, and also about the dangers that beset him and the precautions to be taken, by looking at his eyes or some other part of his body. Yes, they are members and so are we, different things in different ways. All things are filled full of signs, and it is a wise man who can learn about one thing from another. Yet, all the same, many processes of learning in this way are customary and known to all.
Then what is the single linked order? If there is one, our auguries from birds and other living creatures, by which we predict particular events, are reasonable. All things must be joined to one another; not only must there be in each individual thing what has well been termed ‘ a single, united breath of life’, but before them, and still more, in the All. One principle must make the universe a single complex living creature, one from all; and just as in individual organisms each member undertakes its own particular task, so the members of the All, each individual one of them have their individual work to do; this applies even more to the All than to particular organisms, in so far as the members of it are not merely members, but wholes and more important than the members of particular things. Each one goes forth from one single principle and does its own work, but they also co-operate one with another; for they are not cut off from the whole. They act on and are affected by others; one comes up to another, bringing it pain or pleasure. The process has nothing random or casual about it.