Aristotle's Science of Matter and Motion by Christopher Byrne (review)

Physicist Werner Heisenberg famously associated the probability wave of modern theoretical physics with the Aristotelian concept of prime matter. If one takes the concept of the probability wave beyond its meaning in statistical mechanics, then it can be understood as a quantitative version of the traditional concept of potentia. He went on to compare Aristotle's notion of the fundamental material substratum of the universe to the modern concept of mass-energy, pointing out that an accurate account of the ultimate material building blocks of the universe is given in a probability function that refers, not to a specific being, but to the possibility or tendency for being as a manifestation of mass-energy.

Such a positive assessment of Aristotle's conception of matter has hardly been the common view. Far from seeing Aristotle as a forerunner of modern physical theory, many interpreters have held that his conception of matter as mere potentiality for form impeded progress in physics for centuries. According to such interpreters, Aristotle failed to provide any systematic account of matter because he understood the physical universe solely in terms of the specific natures that distinguish perceptible objects from one another. While Aristotle realized that an adequate science of matter must identify a basic material substratum that persists through the various alterations and changes perceptible object undergo, he failed to identify this matter and delineate its common characteristics and behaviors. He treated the material causes of perceptible objects only in terms of the forms of natural substances. Consequently, Aristotelian physics lacks an adequate account of the basic building blocks of physical substances and provides no clear conception of the matter common to perceptible objects.

Christopher Byrne's study of Aristotle's science of matter and motion is a systematic attempt to undermine this now commonplace interpretation. He argues that Aristotle does indeed have a concept of matter apart from his concept of material cause as mere potentiality. The nature of matter becomes manifest in the course of investigations of the material components of perceptible objects. Given that perceptible objects are all physical objects, part of their behavior is explained in terms of their common physicality alone. Whatever is common to any material components is shared by all perceptible objects and is among the causes explaining the being and motion of such objects. This common set of physical attributes is grounded in the physical constitution of perceptible objects and functions in them with a kind of independence from their formal causes. Aristotle's natural science does provide an account of the basic building blocks of the physical universe through a consistent provision of fundamental physical characteristics possessed by any perceptible substance regardless of genus.

Byrne makes the case for his interpretation beginning with an account of the common physical attributes of perceptible objects, such as extension, mobility, a capacity for contact with other bodily objects, and so on. He goes on to show that Aristotle understood these attributes as absolutely necessary in the matter composing perceptible objects as evident in their commonality and invariability. At the same time, Aristotle recognized that these physical characteristics exist and function in natural substances conditionally. The distinction between these natural necessities provides a basis for the division of nonteleological and teleological causes in nature. Basic material causes taken in themselves operate nonteleologically and possess teleological import only as the conditionally necessary physical components for the existence and operation of specific forms.

All of this provides grounds for Byrne's claim that any account that reduces material cause to potentiality alone represents a misinterpretation of Aristotle's conception of matter. The upshot is a reading of Aristotle that emphasizes those ways in which material cause is independent of formal cause. As Byrne puts it, "Aristotle's account of the material causes of perceptible objects is neither the too-empty one of pure potentiality nor the too-full one that contains extraneous non-physical characteristics such as those belonging to living beings."

This reading is systematically...