The Principles of the Philosophy of Nature
Aristotle, through his careful analysis and description of reason’s ordering of its own acts of knowing, developed logic as an art and science of reason. Equipped with the tools of logic which at once reflect and reveal the basic structure of reality and the truth of things, we are now in a position to see how Aristotle and Thomas Aquinas investigate the world as it appears to our senses, that is, what is commonly known (for reasons which we will disclose below) as the natural world. At the heart of this investigation – The Philosophy of Nature – are two of the principal insights Aristotle discovered and developed in his logic. First, that we are able to abstract and, through definitions, identify stable objects of knowledge by predicating universal concepts of particular sensible things. Second, that we discern and distinguish sensible things according to what they are in themselves (the category substance) and the attributes that exist in and through substances (what belong to the other nine categories of accident). From the first insight, Aristotle adapts and develops his particular understanding of ‘form’ and other notions related to it which he will employ in his systematic study of the many and varied objects that we encounter through our senses. From the second insight, that is, the distinction between substance and accident, he will confront and dispel the Problem of Change as bequeathed to the ages by Heraclitus, Parmenides, and Plato.
I. Logical Notions
Substance and Accident – First, as a kind of preliminary and as a tool for philosophical discourse, one should be familiar with the basic distinctions of Aristotle’s logic. The basic logical distinction for our purposes is between substance and accident. This distinction is the basis for Aristotle’s Ten Categories
Forms, Being, and Knowledge – Aristotle built upon what was true in Plato’s insights and realized there must be some principles of stability and knowledge which the mind abstracts and identifies, i.e., specifies, in forming real definitions of natural classes of things. He takes over and adapts Plato’s terminology, continuing to use Plato’s term for his Forms or Ideas (eide) as this principle of knowledge.
II. Change and Motion
The Problem of Change – Next, by analyzing change, Aristotle found that what is actual comes to be from what had been merely potential. In so doing, he identifies the three principles necessary for every change: matter, form and privation.
- Three Principles of Motion
- Accidental Change
- Substantial Change
Motion – For Aristotle, motion is the technical name for the process of something acquiring a new actuality gradually or by stages. While all change is the acquisition of a new actuality or form by something in potency to it (matter), motion refers to those processes whereby such changes occur progressively, the potency becoming more and more actual by degrees until the new form is fully actual.
III. The Four Causes – Aristotle identifies four causes, i.e. four positive principles, for every change. They are what changes, what it changes into, the source of the change and what the change is for.
- Material Cause
- Formal Cause
- Efficient Cause
- General Principles of Causality
- Whatever is moved, is moved by another
- Every agent acts insofar as it is in act
- Nothing causes except by an act which it possesses.
- Principle of Proportionate Causality (resemblance between cause and effects)
- Formal
- Virtual
- Eminent
- Causal Subordination
- Incidental (per accidens)
- Essential (per se)
- First Cause of Motion, Efficient Causality, and Existence
- General Principles of Causality
- Final Cause
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