PHYSICS, BOOK II
© George MacDonald Ross, 1975–1999
Chapter 3
In determining these issues about causes, we must consider what sorts there are, and how many in number. Our concern is with knowledge; but we believe we do not really know a thing until we have grasped its ‘why’, or its original cause. Consequently, it is obvious that here we must do this too in the case of coming into being, ceasing to be, and all physical change. Once we know the beginnings of these, we can then attempt to trace any object of enquiry back to them.
So, one kind of cause is defined as that in a thing out of which it comes into being — for example, the bronze of a statue, the silver of a cup, and the genera to which these belong. Another is the form or model; and this is the definition of the ‘what it was to be’ and its genera — for example, that of the octave is the ratio of two to one, and number in general; and again the components of a definition. Again, there is the first ‘whence the beginning’ of change or its cessation — for example, someone being responsible for something having willed it, the father of the child, and generally that which makes what is made, and changes what is changed. And the final [n.1] kind of cause is the ‘for the sake of which’ — for example, health is the cause of walking. Why does somebody go for a walk? ‘For the sake of their health,’ we say; and in giving this answer we feel we have provided the cause. In addition, there is anything else which happens before the purpose is achieved, but is initiated by a different person — for example (in the case of health) a diet, purgatives, drugs, or surgical tools. All these are for the sake of the same end, and they differ from each other only in that the former is an activity, and the latter are means.
This is an almost precise definition of the types of cause. But it often happens that a number of the causes as defined are causes of one and the same thing, and not just by chance. To use the example of the statue: both the casting and the bronze make the statue what it is rather than something else; but in different ways, since the one is its cause as its matter, and the other as the ‘whence of its motion.’Also some things can be causes of each other. For example, hard exercise is the cause of physical fitness, and physical fitness is the cause of hard exercise — but not in the same way, since the one is the cause as purpose, and the other as the beginning of motion.
Again, one and the same thing can be the cause of opposites, when it is the cause of something by its presence, but sometimes identified as the cause of the opposite by its absence. For example, the absence of the helmsman might be the cause of the sinking of a ship, whereas his presence would have been the cause of its being saved.
All the above mentioned causes come under four very obvious kinds. So phonemes are the causes of syllables; matter of manufactured objects; fire and the suchlike of bodies; parts of a whole; and premises of a conclusion. These are all examples of cause in the sense of the ‘out of which.’ More specifically, some are causes in the sense of being the subject (for example the parts of a whole), and some in the sense of the ‘what it was to be’ — the whole, the synthesis, or the form. Then there are the sperm, the doctor, the voluntary agent, or quite generally anything which acts, all of which are the ‘whence the beginning’ of change, or of cessation of change, or of motion. And finally there is the purpose or supreme good of all the rest; since the ‘for the sake of which’ is usually the noblest, and the purpose of the others (here there is no difference between saying ‘good’, and ‘apparently good’).
These are the causes, and this is the number of species of them. And although there are many variants within each species, these can also be reduced to a small number by being brought under headings. For causes can be described in a variety of ways, and when they belong to the same species, one can be given a more general or a less general description than another. For example, the cause of health might be described as ‘a doctor,’ or ‘a technical expert;’ or that of the octave as ‘the ratio of two to one,’ or ‘number’ — and it is always possible for a more inclusive term to be used instead of a more specific one.
Again, causes can be described in terms of their accidents, or genera of accidents. For example, it could be said that the cause of a statue was either Polycleitus, or a sculptor, since it was accidental to the sculptor that he happened to be Polycleitus — or one could describe the cause of the statue as one of the wider genera including Polycleitus as an accident, such as ‘a human being’ or ‘a living being’ in general. And some accidents are more relevant than others — for example, if the cause of the statue were described as having a fair complexion, or as being skilled in the liberal arts.
Whether a cause is described in terms essential to its being the cause of something or accidental to it, it can also be described either as a potential or an actual cause. For example, the cause of a house being built can be described either as a builder, or as a builder in the act of building.
What we have said about causes also goes for what they are the causes of. For example, a statue can be described as this particular statue, as a statue, or as a representation in general; or again, as this particular piece of bronze, as bronze, or as matter in general. The same is true of their accidents. In addition, what can be said of the former or of the latter can be said of both in combination. For example, instead of talking about ‘Polycleitus’ or ‘the sculptor’, we can talk about ‘Polycleitus the sculptor.’
To summarise, there are only six ways of describing causes, with two variants on each. They may be described in terms of their individuality, their genus, their accidents, the genus of their accidents, in combination, or by themselves. And the variants are whether they are described as the actual causes, or merely potential ones. The difference is that actual causes and what they cause are dependent on each other’s existence. For example, a doctor is a healer only as long as his patient is getting better, and a builder is building only as long as the building is still going up. But this is not always the case when we are talking about potentiality. For a builder does not die if the work on his building stops, and the building is not annihilated if the builder dies.
One should always look for the most important cause of each and every thing. For example, a person builds by virtue of being a builder, and a builder builds by means of the art of building — so the latter is the primary cause. The same is true in all cases.
Again, genera are causes of genera, and individuals of individuals. For example, the genus sculptor is the cause of the genus statue, and this or that sculptor is the cause of this or that statue. Similarly, potential causes are causes of possibles, and actual causes of actuals.
So I have now sufficiently determined how many causes there are, and in what ways they are causes.