On final causality

Aristotle famously argued that in order to exhaustively comprehend an object or substance, you need to know the four causes of it. First there is the material cause, namely that which the object is made out of. Then there is the efficient cause, which is what brings the object into being—this is the type of causation that is commonly referred to when using the word “cause”.  Next there is the formal cause, which is the form, essence, or nature that the object has. Lastly, there is the final cause, which is the end, goal or purpose that something exists for, or that something tends towards.

Now, most contemporary philosophers, and scientists for that matter, admit the reality of efficient causation as well as material causation—though, again, they wouldn’t call the latter a cause—but will not admit the reality of formal and final causes. One reason for this is that final causes are commonly tied with the word “teleology,” and this word is strictly taboo in the scientific domain.

Anyway, it is final causes that will constitute the focal point of this post, and it will be demonstrated that one cannot coherently deny the reality of said causes.

Let me begin by illuminating the nature of final causes—what they are, and are not--so as to avoid confusion. When most individuals hear of final causes and their subsequent tie-in with” teleology,” they tend to think of William Paley’s design argument. That is, they tend to think that the teleology spoken of here is analogous to the teleology imposed upon artificial machines. If artificial machines exhibit complexity coupled with purpose, then other natural objects that exhibit similar complexity must also have been extrinsically endowed with purpose—think here of Paley’s watchmaker illustration. But this is not what is meant by something having a final cause.

Rather, for something to have a final cause simply means for it to have inherent dispositions to reliably bring about a range of effects. That is to say, if an object A regularly brings about B, C or D, then generating B, C or D is the final cause of A. This is what is meant by an end or goal of an object. For example, an acorn reliably generates an oak tree, rather than, say, a weed, or a dog, and thus the oak tree is the end or goal that the acorn is directed towards—that is, the oak tree is the final cause of the acorn. (Note that “directed towards” does not entail that a cause is consciously directed toward an effect. Final causality does not mean that an object is consciously trying to reach said effect, but only that the object tends to produce certain effects reliably.)

Now, although this seems to be intuitive, final causes are nevertheless commonly seen as superfluous. Science, and physics, it is said, makes no use of attributing final causes to things, and therefore we have no reason to believe that such things exist. However, remember 1) that this is completely false, unless one assumes that only science gives us knowledge of reality; 2) the fact that final causes are not pragmatic for science is also irrelevant since final causes are an ontological reality, and thus we’re not looking for them to be pragmatic for science; 3) science does not even enlighten us regarding the intrinsic nature of substances—of which final causality would be a part—but rather only how substances tend to behave; and 4) science actually presupposes final causality, though the substantiation of this assertion will be forthcoming below.

More importantly, science does indeed affirm the reality of efficient causality, and efficient causality actually presupposes final causality. You see, science discovers regularities in nature, hence the formulation of scientific laws. Science works by discovering conditional propositions such as “if A occurs under certain conditions, then B occurs”, or that A’s tend to bring about B’s. But, as Edward Feser says, “there is no way to make sense of these regularities apart from the notion of final causation, of things being directed toward an end or goal.” That is to say, if A reliably brings about B, then producing B is the final cause of A. Now, if substances did not exhibit final causality then one effect would not follow any more than another. Remember also that science doesn’t say that A’s simply happen to be followed by B’s. Rather, it is said, A is a sufficient condition for B, and thus A is inherently directed towards generating B. Again, if there were no final causes then A would not be a sufficient condition for B. Final causality then, far from being superfluous, is a necessary condition for causal regularity.

Again, if substances have final causes, this entails that these substances have certain dispositions to bring about certain effects. And this is what philosophers of science have been saying for quite some time now—that is, that substances have inherent “powers” or dispositions. Edward Feser illuminates my point:

Actual experimental practice indicates that what physicists are really looking for are the inherent powers a thing will naturally manifest when interfering conditions are removed, and the fact that a few experiments, or even a single controlled experiment, are taken to establish the results in question indicates that these powers are taken to reflect a nature that is universal to things of that type.

Again, philosopher of science Brian Ellis:

Scientists today certainly talk about inanimate things as though they believed they had such powers. Negatively charged particles have the power to attract positively charged ones. Electrostatic fields have the power to modify spectral lines. Sulfuric acid has the power to dissolve copper.

That is to say, what science is looking for is precisely what inherent dispositions or powers a substance will produce in ideal circumstances. And this presupposes that there are in fact certain dispositions inherent in these substances that tend to produce a range of effects, and thus it presupposes final causality.

Final causality, then, cannot coherently be denied. That is, unless one wants to deny efficient causation, causal regularity, and science itself. This is why Aquinas called final causes “the cause of causes.”