Aristotle's theory of universals in the context of "Apple"

The history of anatomy spans from the earliest examinations of sacrificial victims to the advanced studies of the human body conducted by modern scientists. Written descriptions of human organs and parts can be traced back thousands of years to ancient Egyptian papyri, where attention to the body was necessitated by their highly elaborate burial practices.

Theoretical considerations of the structure and function of the human body did not develop until far later, in ancient Greece. Ancient Greek philosophers, like Alcmaeon and Empedocles, and ancient Greek doctors, like Hippocrates and his school, paid attention to the causes of life, disease, and different functions of the body. Aristotle advocated dissection of animals as part of his program for understanding the causes of biological forms. During the Hellenistic Age, dissection and vivisection of human beings took place for the first time in the work of Herophilos and Erasistratus. Anatomical knowledge in antiquity would reach its apex in the person of Galen, who made important discoveries through his medical practice and his dissections of monkeys, oxen, and other animals.

Substantial form is a central philosophical concept in Aristotelianism and, afterwards, in Scholasticism. The form is the idea, existent or embodied in a being, that completes or actualizes the potentiality latent in the matter composing the being itself. For Aristotle, in fact, matter is the basis of all that exists; it comprises the potentiality of everything, but of itself is not actually anything. A determinate thing only comes into being when the potentiality in matter is converted into actuality; this is achieved by the substantial form. It is substantial because it is the principle by which a material kind of thing is recognised as such.

This concept was designed by Aristotle to explain several phenomena considered perplexing in the ancient world. One was how physical things can exist as certain types of intelligible things, e.g., Argos and Garmr are both dogs despite being very different because they have the same type of substantial form: it is the substantial form that makes the physical thing intelligible as a particular kind of thing; in other words, such is the Aristotelean solution of the problem of universals. Another one was how the activities of physical things can transcend the limitations of matter to different degrees (for Aristotle, matter was considered unable of any kind of self-organization): plants through their vegetative substantial form transcend the capacities of inanimate matter via growth and nutritive activities; animals through their sentient substantial form by sensation, perception and emotions; and humans by their rational substantial form, so making them "rational animals". A third one was how one physical thing can change into another, e.g. the tiger that eats an antilope not only ends the ability of the antilope's substantial forms to continue animating its prime matter but also enables that same prime matter to become absorbed or animated by the tiger's substantial form. For Aristotle, prime matter is the ultimate principle of physicality and has the potency to being activated by substantial forms into physical entities. Without this potency of prime matter, in Aristotle's opinion, change would either be impossible or would require matter to be destroyed and created rather than altered.