When we speak of chemical affinity, of magnetism, of polarity, we are really speaking in terms of sex. However far we push back our investigations along the lines of evolution we come at length to the distinction which separates one-half of nature from the other, and which is seen to be at the root of all natural attractions and to be the source of generation. Sex, as considered by itself and apart from function and organism, may be the result of a mode of vibration. We cannot say. We may go right back to the first principles of our conception of Life and we find the active and passive principles of Force and Matter, Heat and Moisture, Fire and Water, penetrating through the various philosophies and schools of thought, but always a duality. Even in the Theological conception we have the divine principles of Wisdom and Love in apposition, but united for the purpose of Creation and Preservation of the Universe. It is a mystery that cannot be solved. We cannot in fact, determine whether sex distinction is temporary or eternal. We have reason to regard it as radical and not accidental. For whereas in the process of evolution it appears from time to time to merge in various forms and to become hermaphroditic, we find it continually emerging again, persistent and irrepressible. From the occult point of view it appears to be impounded in the very elements of our being. It has been shown in these pages that the Microcosmic Man is an epitome of the universe, compounded of universal elements, and responsive at all points to the laws controlling the cosmos. It has also been shown that the Moon, so far as this earth is concerned, is the cosmic factor which represents variability. It has also been shown that it exercises first influence in the process of generation, and, therefore we may expect to find it intimately connected with the question of sex. It is, in fact, found to be the factor which determines the astral forces towards the evolution of sex function and organism. By an empiricism based on an occult law and proved by the application of this law to hundreds of cases of well-authenticated births, it has been established that the determination of sex follows a definite course from a certain point of time bearing a mathematical and astronomical relationship to the moment of birth. Thus, given the moment at which a birth took place in any locality, it is possible to at once indicate the sex without the fact being communicated. By this I do not mean that sex production is voluntary in human or animal generation. That is a problem which the Eugenists should consider in the light of the law of sex I am now concerned with.