A Sample Demonstration: The Argument from Efficient Causality
In the
Summa Theologiae Ia 2.3, Aquinas offers five demonstrations for God’s existence (these are famously referred to as the “five ways”). Each demonstration proceeds roughly as follows: Aquinas identifies some observable phenomenon and then attempts to show that, necessarily, the cause of that phenomenon is none other than God. The phenomena Aquinas cites in these demonstrations include: 1) motion; 2) the existence of efficient causes; 3) the reality of contingency; 4) the different grades of perfection in the natural order; and 5) the end-directed activity of natural objects. We should note that these demonstrations are highly abridged versions of arguments he addresses at length elsewhere (most notably,
SCG I.13). Constraints of space do not permit an explication of each argument. But it will be helpful to consider at least one argument in order to see how these demonstrations typically proceed.
Aquinas' argument from efficient causes—also known as "the second way"—is straightforward and does not lend itself to many interpretative disputes. The argument is as follows:
In the world of sense we find there is an order of efficient causes. There is no case known (neither is it, indeed, possible) in which a thing is found to be the efficient cause of itself; for then it would be prior to itself, which is impossible. Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate [cause] is the cause of the ultimate cause, whether the intermediate cause be several, or only one. Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to admit a first efficient cause, to which everyone gives the name of God (
ST Ia 2.3).
For our purposes, it might be helpful to present Aquinas' argument in a more formal way:
- The world contains instances of efficient causation (given).
- Nothing can be the efficient cause of itself.
- So, every efficient cause seems to have a prior cause.
- But we cannot have an infinite regress of efficient causes.
- So there must be a first efficient cause “to which everyone gives the name God.”
First premise. Like all of Aquinas' theistic demonstrations, this one begins by citing an observable fact about the world, namely, that there are causal forces that produce various effects. Aquinas does not say what these effects are, but according to John Wippel, we can assume that these effects would include “substantial changes (generation and corruption of substances) as well as various instances of motion … that is, alteration, local motion, increase, and decrease” (2006: Wippel, 58). Note here that there is no need to prove this premise. Its truth is manifestly obvious, and thus Aquinas employs it as an argumentative point of departure.
Second premise. Aquinas then claims that it is impossible for any being to be the efficient cause of itself. Why is self-causation impossible? For the sake of ease, consider what it would mean for something to be the cause of its own existence (although this is not the only form of self-causation Aquinas has in mind). In order to bring about the existence of anything, one needs a certain amount of causal power. Yet a thing cannot have causal power unless it exists. But if something were to be the cause of
itself—that is, if it were to bring about its own existence—it would have to exist prior to itself, which is impossible (
ST Ia 2.3). Hence the
third premise: every efficient cause must have a prior cause.
Aquinas' argument in the first way—which is structurally similar to the argument from efficient causality—employs a parallel line of reasoning. There, he says that to be in motion is to move from potentiality to actuality. When something moves, it goes from having the ability to move to the activity of moving. Yet something cannot be the source of its own movement. Everything that moves does so in virtue of being moved by something that is
already actual or “in act.” In short, “whatever is in motion must be put in motion by another” (
ST Ia 2.3).
Aquinas' aim here is not to explain discrete or isolated instances of causation. His interest, rather, is the existence of a causal
order—one consisting of substances whose existence and activity depend on prior causes of that same order (Wippel, 59). Yet this attempt to clarify Aquinas' aim introduces an obvious problem. If every constituent member of that order is causally dependent on something prior to itself, then it appears that the order in question must consist of an infinite chain of causes. Yet Aquinas denies this implication (
fourth premise): if the causal order is infinite, then (obviously) there could be no first cause. But without a first cause, then (necessarily) there could be no subsequent effects—including the intermediate efficient causes and ultimate effect (
ST Ia 2.3). In other words, the absence of a first cause would imply an absence of the causal order we observe. But since this implication is manifestly false, he says, there must be a first cause, “to which everyone gives the name God” (Ibid.).
A few clarifications about this argument are in order. First, commentators stress that this argument does
not purport to show that the world is constituted by a temporal succession of causes that necessarily had a beginning (see for example Copleston, 1955: 122-123). Interestingly, Aquinas himself denies that the argument from efficient causality contradicts the eternality of the world (
ST Ia 46.2 ad 1). Whether the world began to exist can only be resolved, he thinks, by appealing to sacred teaching. Thus he says that “by faith alone do we hold, and by no demonstration can it be proved, that the world did not always exist" (
ST Ia 46.2). With respect to the second way, then, Aquinas' aim is simply to demonstrate that the order of observable causes and effects cannot be a self-existing reality.
An illustration may help clarify the sort of argument Aquinas wishes to present. The proper growth of, say, plant life depends on the presence of sunlight and water. The presence of sunlight and water depends on ideal atmospheric activities. And those atmospheric activities are themselves governed by more fundamental causes, and so forth. In this example, the events described proceed not sequentially, but concurrently. Even so, they constitute an arrangement in which each event depends for its occurrence on causally prior events or phenomena. According to Copleston, illustrations of this sort capture the kind of causal ordering that interests Aquinas. For “when Aquinas talks about an ‘order’ of efficient causes he is not talking of a series stretching back into the past, but of a hierarchy of causes, in which a subordinate member is here and now dependent on the causal activity of a higher member” (Copleston, 1955: 122). Thus we might explain the sort of ordering that interests Aquinas as a
metaphysical (as opposed to a temporal) ordering of causes. And it is
this sort of order that requires a first member, that is, “a cause which does not depend on the causal activity of a higher cause” (Ibid., 123). For, as we have already seen, the absence of a first cause would imply the absence of subsequent causes and effects. Unless we invoke a cause that itself transcends the ordering of dependent causes, we would find it difficult to account for the causal activities we presently observe. Aquinas therefore states there must be “a first efficient, and completely non-dependent cause,” whereby “the word ‘first’ does not mean first in the temporal order but supreme or first in the ontological order” (Ibid.: 123; For valuable commentaries on these points, see Copleston, 122-124; Wippel, 2006: 59; Reichenbach, 2008).
Second, it may appear that Aquinas is unjustified in describing the first efficient cause as
God, as least if by “God” one has in mind a person possessing the characteristics Christian theologians and philosophers attribute to him (for example, omniscience, omnipotence, omnipresence, love, goodness, and so forth.). Yet Aquinas does not attempt to show through the previous argument that the demonstrated cause has any of the qualities traditionally predicated of the divine essence. He says: “When the existence of a cause is demonstrated from an effect, this effect takes the place of the definition of the cause in proof of the cause's existence” (
ST Ia 2.2
ad 2). In other words, the term
God—at least as it appears in
ST Ia 2.2—refers only to that which produces the observed effect. In the case of the second way,
God is synonymous with the first efficient cause; it does not denote anything of theological substance. We might think of the term “God” as a purely nominal concept Aquinas intends to investigate further (Te Velde, 2006: 44; Wippel, 2006: 46). For the study of
what God is must be subsequent to demonstrating
that he is. A complete account of the divine nature requires a more extensive examination, which he undertakes in the subsequent articles of
ST.
Aquinas’ Philosophical Theology | Internet Encyclopedia of Philosophy
That's where the argument came from and is.
I believe that it was also you that claimed that a god was necessary as opposed to contingent by definition.
I claim that is what Plantinga and other philosophers classify God as.
Your claim about causality has already been refuted. Most recently, Polymath described quantum indeterminacy to you.
1. We did not discuss indeterminacy that I can remember, and it was not explained. 2. Even if it was explained it is merely a possibility, or at least it is not known to be impossible. 3. The last time I had the misfortune to be at a faculty speech the physicist said there were about (at that time) 10 possible ways to interpret quantum mechanics, about half were indeterminate and half were deterministic and no one was sure which (if any) were true. Only the tiniest fraction of scholars have credibility concerning QM, Polymath demonstrated that they potentially were among that handful. Until you demonstrate you are competent, you just come off as desperate and arrogant.
As already noted, that argument has also been refuted, most recently on this thread.
It is still just as un-refuted today as it was 3000 years ago. Just because someone continues to talk does not mean they are getting anything done. This also was not an argument, it was a proxy declaration.