Isis is, in fact, the female principle of Nature, and is receptive of every form of generation, in accord with which she is called by Plato​ the gentle nurse and the all-receptive, and by most people has been called by countless names, since, because of the force of Reason, she turns herself to this thing or that and is receptive of all manner of shapes and forms. She has an innate love for the first and most dominant of all things, which is identical with the good, and this she yearns for and pursues; Fbut the portion which comes from evil she tries to avoid and to reject, for she serves them both as a place and means of growth, but inclines always towards the better and offers to it opportunity to create from her and to impregnate her with effluxes and likenesses in which she rejoices and is glad that she is made pregnant and teeming with these creations. For creation is the image of being in matter, and the thing created is a picture of reality.

It is not, therefore, out of keeping that they have a legend that the soul of Osiris is everlasting and imperishable, but that his body Typhon oftentimes dismembers and causes to disappear, and that Isis wanders hither and yon in her search for it, and fits it together again;​ for that which really is and is perceptible and good is superior to destruction and change. The images from it with which the sensible and corporeal is impressed, and the relations, forms, and likenesses which this take upon itself, like impressions of seals in wax, are not permanently lasting, but disorder and disturbance overtakes them, Bbeing driven hither from the upper reaches, and fighting against Horus,​ whom Isis brings forth, beholden of all, as the image of the perceptible world. Therefore it is said that he is brought to trial by Typhon on the charge of illegitimacy, as not being pure nor uncontaminated like his father, reason unalloyed and unaffected of itself, but contaminated in his substance because of the corporeal element. He prevails, however, and wins the case when Hermes,​ that is to say Reason, testifies and points out that Nature, by undergoing changes of form with reference to the perceptible, duly brings about the creation of the world. The birth of Apollo from Isis and Osiris, while these gods were still in the womb of Rhea, has the allegorical meaning that before this world was made visible and its rough material was completely formed by reason, it was put to the test by Nature and brought forth of itself the first creation imperfect. This is the reason why they say that this god was born in the darkness a cripple, and they call him the elder Horus;​ for there was then no world, but only an image and outline of a world to be.