Out of these emotions, and the thoughts which are bound up with them, clairvoyant organs are formed. Should the plant be added to the contemplation, one will notice that the feeling outflowing from it, both in its quality and in its degree, lies between that which emanates from the stone and that from the animal. The organs which are so formed are spiritual eyes. We learn by degrees and through their means to see both astral and mental colors. As long as one has attained only the condition described as Probation, the spiritual world with its lines and figures remains dark, but through Enlightenment it will become clear. It must be noted here that the words "dark" and "light," as well as the other common expressions, only approximately describe what is really meant; for language as usually understood is constructed to suit physical conditions alone. Occult science describes what emanates from the stone and is seen by clairvoyant eyes, as "blue" or "bluish-red," and that which is observed as coming from the animal is described as "red" or "reddish-yellow." In reality they are colors of a spiritual kind which are discerned. The color proceeding from the plant is "green." Plants are just those natural phenomena whose qualities in the higher worlds are similar to their qualities in the physical world, but it is not so with stones and animals. It must now be clearly understood that the above-mentioned colors only suggest the prevailing shades of the stone, the plant, or the animal. In reality, all possible overtones exist, for every animal, every stone, every plant has its own peculiar shade of color. In addition to these there are the creatures of the higher worlds, who always incorporate themselves with colors not their own, often marvellous, often horrible. In short, the variety of colors in these higher worlds is immeasurably greater than in the physical world. If a man has once acquired the faculty of seeing with spiritual eyes, he sooner or later, meets with the beings here mentioned, some of them higher, some lower than man himself; beings who never entered into physical existence. When he has advanced thus far, the way to a great deal lies open before him; but it is inadvisable to proceed further without an experienced guide. Indeed, for all that has here been described, such experienced guidance is desirable, and he who has the endurance to fulfil the elementary conditions of enlightenment, will assuredly seek and discover his guide.