A monumental philosophical
work written by Aristotle
concerning the nature
of, parts of, and types of the soul
. Literally meaning "On The Soul
", this work
explains much of Aristotle's theory
of human nature
. It is thorough
in its description of the function
of the soul. He establishes it as the defining characteristic
that separates living things from all other existent
s. Aristotle differs from his predecessor
s in determining that an advanced understanding
of the soul was needed to fully grasp the concept
, particularly in the context
of the human intellect
. He was careful to make the distinction between the soul of an animal
and that of a human being
. From De Anima
"For perishable things that have reasoning also have all other parts of the soul; but not all of those that have each of the other parts also have reasoning - on the contrary, some animals lack appearance, while some live by appearance alone. 1 Theoretical intellect requires a different account." 2
Book I : Introduction to the Study of the Soul
In this section of the work, Aristotle works through some of the problems associated with studying the soul, and outlines many of the previous attempts to give such an account by his predecessors. Many philosophers working with idea before him approached the soul in terms of the matter of which is was composed. Diogenes and the Pythagoreans claimed that the soul was made of air; Democritus thought it was a primary, indivisible element, while Heraclitus theorized it to be comprised of hot vapor.
None of these definitions satisfied Aristotle, and he carefully works through these ideas to discover the problems with them. He further examines the work of Democritus:
"Some people say that the soul is itself in motion and thereby initiates the same sort of motion in the body that it belongs to. This is what Democritus says ... for he says that the indivisible spheres are in motion, because it is in their nature never to be at rest, and that they drag along the whole body and set it in motion." 3
Aristotle argues against this claim, stating that if these indivisible particles are responsible for movement, then the same element must be responsible for the body coming to rest. He thinks it is difficult to delineate this process, as it seems to require some sort of decision or thought process, beyond a mere physical component.
He progresses to work with Plato's account of the soul outlined in the Timaeus. He thinks that any account of Plato's type leads to indefinite conclusions. The Timaeus defines the soul as being attached or trapped somehow in the body. Aristotle doubts this notion, as no real process is ever outlined as to what causes this attachment and its specific nature. He goes on to examine another Platonic understanding of the soul put forth in the Phaedo, 4 that the soul is some type of harmony of contrasting elements, and the body results from this combination. Aristotle argues that this sort of idea could only be understood in a physical sense, and that a blending of this kind can not be realized in terms of a thing such as the soul.
Book II : Definition of the Soul
After having sorted through the views held on the soul previous to his work, Aristotle seeks to begin to outline what the soul is in this section. He makes the distinction between living and non-living things, stating that anything living must have the ability to perform certain processes to further its own existence. Beyond this, there are three types of souls, all of which share that characteristic:
- Nutritive : This category consists of plants. At a basic level, plants have the capacity to grow and decay according to a simple set of processes that it follows. They maintain their own nutritive levels, and will continue to be alive as long as they are able to absorb nutrients from their environment.
- Perceptual : This category consists of animals. Aristotle states that touch is the most basic form of perception, and an animal may have this sense without any others. Locomotion is also not necessary in this category, though some might possess it. Animals have the nutritive part to their soul as well, but in a more advanced way. They can perceive the way in which they are nourished. For example, in some cases, they can discriminate more precisely between that which is hot or cold, wet or dry.
- Knowledgeable : This category consists of human beings. Humans have nutritive and perceptual capabilities, but it is their capacity for theoretical knowledge that sets them apart from animals and plants. In this category, there are three different levels of actualizing this capacity according to Aristotle:
Book III : Connections Between the Senses
In this section of De Anima, Aristotle seeks to connect the various parts of the soul and the senses that he outlined in the previous sections. He argues that intellect is receives the form of its objects through perception, and in that way, becomes one with the object. Also, he makes the distinction that the mind does not have content until it thinks (tabula rasa), contrary to the work of Plato. The intellect takes its concepts from matter. From his outline of Understanding in Book III:
"The condition of the sense-organ and of the faculty of perception makes it evident that the perceiving part and the intellectual part are ... different. For after a sense perceives something very perceptible, it cannot perceive; after hearing very loud sounds, for instance, it cannot hear sound, and after seeing vivid colors or smelling strong odors, it cannot see or smell. But whenever intellect understands something that is very intelligible, it understands more, not less, about inferior objects ... " 5
1 appearance alone, meaning without reason.
2 Aristotle. De Anima. tr. Terence Irwin and Gail Fine. p. 415 a.
3 p. 406 b.
4 Plato. Phaedo. tr. G. M. A. Grube. Stephanus pp. 86 c-d.
5 p. 429 b.