Aristotle’s De Animus, and Steiner's Fourfold Man
Aristotle, in his treatise On the Soul, or De Animus, has described a concept of the human psyche which was the basis for Rudolf Steiner's modern-day reformulation of the idea into the concept of the four-fold man. Aristotle describes three different parts of the human soul, each with its counterpart in the kingdoms of nature. The purely material part of living beings, which Steiner calls the physical body, is not described here because it is not considered by Aristotle to be a part of the soul.
1. The Soul of Life Forces
The most basic kind of soul is that which is held in common by all living things. Plants, animals and human beings all have it. It is the power of life, with its attributes of nutrition, reproduction, growth and decay.
“The power of self-nutrition can be isolated from the other powers mentioned, but not they from it – in mortal beings at least. The fact is obvious in plants; for it is the only psychic power they possess.” 413a (32)
“It follows that first of all we must treat of nutrition and reproduction, for the nutritive soul is found along with all the others and is the most primitive and widely distributed power of soul, being indeed that one in virtue of which all are said to have life.” 415a (22)
“The first soul ought to be named the reproductive soul.” 416b (24)
“The movement of growth and decay, being found in all living things, must be attributed to the faculty of reproduction and nutrition, which is common to all…” 432b (10)
“The nutritive soul then, must be possessed by everything that is alive, and every such thing is endowed with soul from its birth to its death. For what has been born must grow, reach maturity, and decay – all of which are impossible without nutrition. Therefore the nutritive faculty must be found in everything that grows and decays.” 434a (22)
Students of Rudolf Steiner will recognize the "life body" or "etheric body" in this aspect of soul as described by Aristotle.
2. The Soul of Desires
The second kind of soul is not possessed by plants, but only by animals and human beings. It is the soul-faculty which confers the powers of sensation, desire, appetite, pleasure and pain.
“…but it is the possession of sensation that leads us for the first time to speak of living things as animals; for even those beings which possess no power of local movement but do possess the power of sensation we call animals and not merely living things.” 413b (2)
“…for, where there is sensation, there is also pleasure and pain, and, where these, necessarily also desire.” 413b (23)
“Hence we must ask in the case of each order of living things, What is its soul, i.e. What is the soul of plant, animal, man? …But the facts are that the power of perception is never found apart from the power of self-nutrition, while – in plants – the latter is found isolated from the former.” 414b (32)
Students of Rudolf Steiner will recognize the "astral body" in this aspect of soul as described by Aristotle.
3. The Soul of Reason
The third kind of soul faculty is found only in human beings, although Aristotle indicates the possibility that a higher order of beings may also possess it. This is the power of thought, consciousness, reason. This is the imperishable, the immortal part of the soul.
“We have no evidence as yet about mind or the power to think; it seems to be a widely different kind of soul, differing as what is eternal from what is perishable; it alone is capable of existence in isolation from all other psychic powers.” 413b (24)
“Of the psychic powers above enumerated some kinds of living things, as we have said, possess all, some less than all, others one only. Those we have mentioned are the nutritive, the appetitive, the sensory, the locomotive, and the power of thinking. Plants have none but the first, the nutritive, while another order of living things has this plus the sensory. If any order of living things has the sensory, it must also have the appetitive; for appetite is the genus of which desire, passion, and wish are the species; now all animals have one sense at least, viz. touch, and whatever has a sense has the capacity for pleasure and pain and therefore has pleasant and painful objects present to it, and wherever these are present, there is desire, for desire is just appetition of what is pleasant… And still another order of animate beings, i.e. man and possibly another order like man or superior to him, the power of thinking, i.e. mind.” 414a (29)
“Lastly, certain living beings – a small minority – possess calculation and thought, for (among mortal beings) those which possess calculation have all the other powers above mentioned, while the converse does not hold…” 415a (6)
“That perceiving and practical thinking are not identical is therefore obvious; for the former is universal in the animal world, the latter is found in only a small division of it.” 427b (6)
“Mind is not at one time knowing and at another not. When mind is set free from its present conditions it appears as just what it is and nothing more: this alone is immortal and eternal (we do not, however, remember its former activity because, while mind in this sense is impassible, mind as passive is destructible), and without it nothing thinks.” 430a (22)
“…for those who successfully resist temptation have appetite and desire and yet follow mind and refuse to enact that for which they have appetite.” 433a (6)
“Since appetites run counter to one another, which happens when a principle of reason and a desire are contrary and is possible only in beings with a sense of time, for while mind bids us hold back because of what is future, desire is influenced by what is just at hand…” 433b(5)
Paying particular attention to the last two quotes, we begin to discern a dynamic between the two higher parts of the soul. The sensory-appetitive soul is drawn to partake of whatever pleasure or desire it perceives in its immediate environment. It does not discriminate between those appetites which are, on the one hand, healthful, beneficial and fully compatible with our future goals and long term happiness, and those which, on the other hand, although very attractive on the short term, will be liable to get us into trouble later and come with a price which, on sober reflection, is too high.
Students of Rudolf Steiner will recognize the "ego" in this aspect of soul as described by Aristotle.