Aristotle (De Anima, II. 2, 3) further states that the soul is to be determined in three ways, namely as nutrient or vegetable, as sensitive, and as intelligent, corresponding with plant life, animal life and human life. The nutrient soul, when it is alone, belongs to plants; when it is at the same time capable of sense-perception, it is the animal soul; and when at once nutrient, sensitive and intelligent, it is the mind of man. Man has thus three natures united in himself; a thought which is also expressed in modern Natural Philosophy by saying that a man is also both an animal and a plant, and which is directed against the division and separation of the differences in these forms. That difference has also been revived in recent times in the observation of the organic, and it is highly important to keep these sides separate. The only question (and it is Aristotle who raises it) is how far these, as parts, are separable. As to what concerns more nearly the relation of the three souls, as they may be termed (though they are incorrectly thus distinguished), Aristotle says of them, with perfect truth, that we need look for no one soul in which all these are found, and which in a definite and simple form is conformable with any one of them. This is a profound observation, by means of which truly speculative thought marks itself out from the thought which is merely logical and formal. Similarly among figures only the triangle and the other definite figures, like the square, the parallelogram, &c., are truly anything; for what is common to them, the universal figure, is an empty thing of thought, a mere abstraction. On the other hand, the triangle is the first, the truly universal figure, which appears also in the square, &c., as the figure which can be led back to the simplest determination. Therefore, on the one hand, the triangle stands alongside of the square, pentagon, &c., as a particular figure, but—and this is Aristotle’s main contention—it is the truly universal figure. In the same way the soul must not be sought for as an abstraction, for in the animate being the nutritive and the sensitive soul are included in the intelligent, but only as its object or its potentiality; similarly, the nutritive soul, which constitutes the nature of plants, is also present in the sensitive soul, but likewise only as being implicit in it, or as the universal. Or the lower soul inheres only in the higher, as a predicate in a subject: and this mere ideal is not to be ranked very high, as is indeed the case in formal thought; that which is for itself is, on the contrary, the never-ceasing return into itself, to which actuality belongs. We can determine these expressions even more particularly. For if we speak of soul and body, we term the corporeal the objective and the soul the subjective; and the misfortune of nature is just this, that it is objective, that is, it is the Notion only implicitly, and not explicitly. In the natural there is,