1.1.1. The Threefold Meaning of the Word ‘Causality’
The word ‘causality’ has, unfortunately enough, no fewer than three principal meanings—a clear symptom of the long and twisted history of the causal problem. The single word ‘causality’ is in fact used to designate: (a) a category (corresponding to the causal bond); (b) a principle (the general law of causation), and (c) a doctrine, namely, that which holds the universal validity of the causal principle, to the exclusion of other principles of determination.
In order to minimize the danger of confusion, it will be convenient to try to keep to a definite nomenclature in correspondence with such a semantic variety. Let us designate by:
(a) causation, the causal connection in general, as well as any particular causal nexus (such as the one obtaining between flames in general and burns produced by them in general, or between any particular flame and any particular burn produced by it);
(b) causal principle, or principle of causality, the statement of the law of causation, in a form such as The same cause always produces the same effect, or any similar (and preferably refined) one. It will be convenient to restrict the term ‘causal law’ to particular statements of causal determination, such as “Flames invariably cause burns in the human skin”; finally,
(c) causal determinism, or causalism, and often simply causality, the doctrine asserting the universal validity of the causal principle. A few formulations of the kernel of this theory are: “Everything has a cause”, “Nothing on earth is done without a cause”, “Nothing can exist or cease to exist without a cause”, “Whatever comes to be is necessarily born by the action of some cause”, and “Everything that has a beginning must have a cause”.
In short, while the causal principle states the form of the causal bond (causation), causal determinism asserts that everything happens according to the causal law.
1.1.2. Causation: A Purely Epistemological Category of Relation, or an Ontological Category?
As here understood, causation is synonymous with causal nexus, that connection among events which Galileo1 described as “a firm and constant connection”, and which we shall try to define more accurately in Chapter 2. But what is the status of the category of causation? Is it a form of interdependence, and has it consequently an ontological status? Or is it a purely epistemological category belonging solely, if at all, to our description of experience?
The modern controversy over this question began with the skeptic and empiricist criticism. According to modern empiricism, the status of the causation category is purely epistemological, that is, causation concerns solely our experience with and knowledge of things, without being a trait of the things themselves—whence every discourse on causation should be couched in the formal, not in the material, mode of speech.2 Thus Locke3 proposed the following definitions: “That which produces any simple or complex idea, we denote by the general name ‘cause’, and that which is produced, ‘effect’. Thus finding that in that substance which we call ‘wax’ fluidity, which is a simple idea that was not in it before, is constantly produced by the application of a certain degree of heat, we call the simple idea of heat, in relation to fluidity in wax, the cause of it, and fluidity the effect”. Moreover, like Kant after him, Locke held the causal principle to be “a true principle of reason”: a proposition with a factual content but not established with the help of the external senses.
The conception of causation as a mental construct, as a purely subjective phenomenon, was emphasized by Locke’s followers Berkeley4 and Hume,5 as well as by Kant.6 But, whereas Locke had regarded causation as a connection, acknowledging production as its distinctive mark, his followers have held that causation is only a relation,7 and moreover one relating experiences rather than facts in general. Hume emphasized this point particularly, on the ground that it would not be empirically verifiable that the cause produces or engenders the effect, but only that the (experienced) event called ‘cause’ is invariably associated with or followed by the (experienced) event called ‘effect’—an argument which is of course based on the assumption that only empirical entities shall enter any discourse concerning nature or society.
The empiricist doctrine of causality will be examined rather closely in the course of this book, especially as it is a widespread belief that Hume gave the final, or almost final, solution of the causal problem. For the time being we shall merely state the opposite thesis, namely, that causation is not a category of relation among ideas, but a category of connection and determination corresponding to an actual trait of the factual (external and internal) world, so that it has an ontological status—although, like every other ontological category, it raises epistemological problems.8 Causation, as here understood, is not only a component of experience but also an objective form of interdependence obtaining, though only approximately, among real events, i.e., among happenings in nature and society.
But before we can ascertain whether causation is a category of determination, and long before we can hope to show that, while being so far used in both science and philosophy, it is not the sole category of determination, we shall have to examine what is meant by ‘determination’.