The Atlas of Reality
Page 95
At any rate, we are left to ask whether infinite causal regresses are possible. Many metaphysicians have found the idea absurd. If causal regresses were possible, then very specific structures and bodies of information could be self-causing and self-explaining. For example, one could imagine a world in which Tolstoy's novel War and Peace exists, even though no one ever created it. The story of the novel could simply be passed from one reader to another in an infinite regress, without an original author.
Impossibility of Causal Regresses. It is impossible for there to exist an infinite causal regress, that is, a series x1, x2, and so on of such a kind that x1 is caused by x2, x2 by x3, x3 by x4, and so on ad infinitum.
In addition, there are a number of arguments against the possibility of infinite causal regresses. The Grim Reaper paradox discussed in Section 19.1.2 provides the basis for one such argument. The argument requires a patchwork principle (PMeta 5.1/5.2). The basic idea is that if a certain kind of causal structure C, like an infinite regress, is possible, and a certain situation S consisting in the possession of certain causal powers and dispositions is possible, then there is a possible world in which the possible structure C is realized by placing a situation like S at every node in the structure.
This seems plausible, so long as the powers and dispositions that define the relations among the S-like situations are truly intrinsic to those situations. That is, this argument requires the Intrinsicality of Powers (PMeta 2). As we saw in Chapter 5, Neo-Humeists will disagree with this assumption, taking causal powers to be extrinsic to the things that possess them. According to Neo-Humeism, whether a thing has a certain causal power depends on the whole history of the world. Thus, Neo-Humeists have no reason to reject the possibility of infinite causal regresses, while those who see causal powers and dispositions as intrinsic to the things that have them do have good reason to think such regresses impossible.
In addition, the critic of the Grim Reaper argument can object to the patchwork principles. One could appeal to Sydney Shoemaker's Branch Principle (see Section 6.2.1) as a basis for this objection. If every possible world must branch off from the actual world at some point in time, then we have good independent grounds for rejecting the possibility of the infinite regress of Grim Reapers, so long as the actual world contains no such causally perverse regress.
26.2.2 Uncaused causes
If both self-causation and causal regresses are impossible and there is causation, then Special Causation must be true. In addition, the impossibility of both self-causation and infinite regresses entails that there must exist uncaused or “first” causes:
26.1T.1A.1T Existence of Uncaused Causes. Some uncaused things cause other things.
If there are such uncaused causes, what are they like? The only way for us to tell would be for us to appeal to some causal principle, a principle that states that everything of type K has a cause. We could then infer that all uncaused things are not of type K.
Here are some causal principles that have been proposed in the history of metaphysics:
Causal Principle: Contingency-Based. Every contingent thing is caused, and no necessary thing is caused. Proposed by al-Farabi (Craig 1980: 76–85), Avicenna or ibn Sina (Craig 1980: 86–97), Thomas Aquinas (Craig 1980: 158–204; Kretzmann, 1997), Samuel Clarke (Clarke 1704/1998), and Richard Taylor (Taylor 1991: Chapter 11).
Causal Principle: Scotistic. Every causable thing is caused. Proposed by John Duns Scotus (Scotus 1307/1987: 34–81).
Causal Principle: Kalaam. Everything that begins to exist is caused, and no beginningless thing is caused. Proposed by the medieval Kalaam philosophers, including al Kindi and al Ghazzali (Craig 1980: 61–75, 98–104), and defended more recently by William Lane Craig (Craig 1979; see also Koons 2014a).
Causal Principle: Quantitative. Every finite thing (i.e., every thing with a finitely measurable attribute) is caused, and no infinite thing is caused. Proposed by Duns Scotus (Scotus 1307/1987: 34–81; see also Koons 1997).
The Contingency-Based Causal Principle entails that all uncaused things are necessary beings, that is, beings that exist necessarily. The Scotistic Principle entails that all actually uncaused things are uncausable, the Kalaam Principle entails that no uncaused things began to exist, and the Quantitative Principle entails that all uncaused things are infinite, in the sense of lacking any attribute with a finite measure. The Quantitative Principle relies on the intuition that whenever something has a finite measure, there must be some causal explanation of why it has exactly that measure, rather than one slightly greater or slightly less. Hence, an uncaused thing must lack any such measurable attribute. All of its attributes must be absolutely unmeasurable or must have attributes that are metrically isolated, like the values 0 or absolute infinity.
Historically, these principles have been employed in proving the existence of God, with God understood as necessary, uncausable, beginningless, and infinite, and the cause of all other things. To pursue this question would require more space than we can spare here, but we will note that the First Cause argument as we've developed it does not by itself establish the existence of a unique first cause.
Must there be some such true causal principle? Could the set of caused things be undefinable? The main argument for the definability of a causal principle involves the claim that unprincipled causation would be incompatible with our having empirical knowledge. Consider any body of empirical data, including sensory experience, memories, physical traces, and testimony. If it is metaphysically possible for any of the data to exist uncaused, then it would seem prima facie possible for all of it to exist uncaused. However, the possibility that our empirical data is uncaused would be what epistemologists describe as an undercutting defeater to any claim to know something on the basis of that data. Uncaused perception, memories and so on cannot produce knowledge. If we cannot rule out the possibility that our data is uncaused, the live possibility that we do not in fact have knowledge might be enough to deprive us of knowledge in actuality. This possibility, if it cannot be rationally dismissed, would defeat any of the usual evidence for our claims to knowledge, since we would have to take seriously the possibility that all that evidence began to exist without any cause whatsoever.
Since the whole body of our empirical information could be vulnerable to this kind of defeater, we must be able to rule out the possibility that the information is uncaused on a priori, pre-empirical grounds. This would seem to require our having a priori knowledge of some appropriate causal principle, that is, knowledge that is prior to and independent of our empirical, scientific knowledge.
Any of the four principles listed above, if they could be known a priori, would preserve the possibility of empirical knowledge, since it is plausible to think that we can know a priori that all of our empirical knowledge is contingent, causable, finite, and had a beginning in time (see Koons 2008 for additional details).
OBJECTIONS TO THE FIRST CAUSE ARGUMENT There are two sorts of objections that could be lodged to these traditional First Cause arguments. First of all, one could object to Special Causation, which would involve arguing either that self-causation is possible or that causal infinite regresses are possible (or both).
A second sort of objection would involve accepting Special Causation but rejecting all of the Causal Principles. Such a position concedes that there are first or uncaused causes but denies that we can know anything about them. This is the thesis of Unprincipled Special Causation:
26.1T.1A.2A Unprincipled Special Causation. Some things are caused and others are not, and the two categories of things are in every other respect indistinguishable.
Defenders of Unprincipled Special Causation will still have to cope somehow with the problem of the defeat of our empirical knowledge by the fact that any of our evidence could have sprung into existence without cause. Without a principle of causation, there is no way to keep the possibility of uncaused events from penetrating deeply into the natural world—into our brains and our immediate environment.
&nb
sp; The most common way of arguing for Unprincipled Special Causation is to argue that the sorts of things required by the various causal principles (Contingency-Based, Scotistic, etc.) are impossible. Here are the corresponding four types of objections:
Type 1: it is impossible for anything to exist necessarily. (Against the Contingency-Based Causal Principle)
Type 2: it is impossible for anything to be uncausable. (Against the Scotistic Principle)
Type 3: necessarily, everything began to exist at some point in time. (Against the Kalaam Principle)
Type 4: it is impossible for anything to be infinite in measure. (Against the Quantitative Causal Principle)
We will focus here on objections of Type 1, which are historically the most significant.
Hume's Objection: Imagination is the guide to possibility, and we can imagine the non-existence of anything.
In Dialogues concerning Natural Religion (Hume 1779), David Hume argued that the postulation of a necessarily existing being is absurd, since anything we can conceive of, we can conceive of as not existing. Hence, either we cannot conceive of a necessary being at all, or, if we can conceive of it, we can conceive of it as not existing. Anything we can conceive of as not existing, we must conceive of as possibly not existing, and so as not necessary. Thus, we cannot conceive of a necessary being at all.
We could take Hume to be appealing to Imagination as Guide to Possibility (PEpist 1). The argument might go something like this:
To exist necessarily is to be something whose non-existence is inconceivable.
If we can imagine the existence of something, then we can imagine its non-existence.
Hence, we cannot imagine the existence of something that exists necessarily. (From 1 and 2)
If we cannot imagine the existence of something, then we have strong grounds for denying its possibility. (Imagination as Guide to Possibility, PEpist 1)
Hence, we have strong grounds for denying the possibility of something that exists necessarily. (From 3 and 4)
However, as we have seen, imagination seems to be at best a fallible guide to possibility. So, even if it were true that anything we have a concept of is something we can imagine not existing, it doesn't follow that everything we have a concept of is possibly not existent (i.e., not something existing necessarily).
In addition, it is not at all clear that we can imagine something's not existing (contrary to step 2 of the argument), except under very special circumstances. If one knows that the Mona Lisa couldn't have existed without da Vinci's taking up painting, and one can imagine da Vinci's not being a painter (by imagining his spending his life sculpting instead), then one can (indirectly) imagine the Mona Lisa's not existing. Similarly, if one knows that electrons could not have existed unless the Big Bang reached a certain point of symmetry breaking, and one can imagine the Big Bang's not reaching that point, then one can imagine the non-existence of electrons. However, the concept of a necessary being doesn't seem to involve that thing's being dependent in any way on prior conditions, so it is far from obvious what it would be like to imagine such a being's non-existence.
Kant's Objection: The existence of a necessary being entails the validity of Anselm's ontological argument, but that argument is invalid.
In the “Transcendental Dialectic” section of The Critique of Pure Reason (Kant 1781/1787), Immanuel Kant argued that it is impossible to conceive of the existence of a necessary being. Kant argued that a necessary being would have to be a being whose existence was a logical truth, in the sense that it is a logical consequence of the basic axioms of logic and a set of coherent definitions. A necessary being would have to be the kind of thing that, in effect, exists by definition alone. For example, Anselm of Canterbury proposed that our concept of God is the concept of an absolutely perfect being, and perfection includes existence by definition. Hence, to suppose that God (so defined) doesn't exist would be self-contradictory, just like supposing that there is a triangle that doesn't contain three angles. This is one version of Anselm's ontological argument from his Proslogion (Anselm 1059/1998: 82–90—the name ‘ontological’ was first given to this argument by Kant in The Critique of Pure Reason).
However, Kant points out that nothing can exist by definition. You can define any sort of thing you want in any way, but you cannot possibly guarantee that there really is something that fits your definition. Even if the definition of ‘God’ included existence, there would still be an open question as to whether there exists anything in reality that fits the definition.
Kant's argument could be summarized thus:
A necessary being is one that exists as a matter of logical truth, that is, as a consequence of a set of definitions.
There is nothing that exists as a matter of logical truth, since no set of definitions by itself entails the existence of anything.
So, there is and can be no necessary being.
The defender of necessary beings must challenge premise 1. Logical truth is just one kind of necessary truth. A necessary being is simply a being that couldn't not have existed. There is no requirement that the non-existence of the being somehow contradicts a definition or the laws of logic.
Additionally, Kant's position is an unstable one. Supposed we ask whether premise 1 of Kant's argument is necessary or contingent. If Kant says it is necessary, then he must claim that it is a logical truth. This would mean that premise 1 follows from the definitions and the laws of logic. But, how can it? We haven't defined necessary truth as logical truth. If, instead, Kant supposes that premise 1 is a contingent truth, then we can ask on what basis does he accept it? If it could have been the case that some being existed necessarily but not as a matter of logical truth, then why couldn't that be true in the actual world?
Note
1. In the middle of the twentieth century, an attempt was made by philosophers like Richard Jeffrey (Jeffrey 1965) to give a completely non-causal theory of decision-making. This non-causal decision theory relied entirely on subjective conditional probabilities. On this view, it is rational to choose to do action A just in case the conditional probability of good results, given A, is higher than the probability of those same goods conditional on any other action.
However, this non-causal decision theory was found to break down when considering certain possible choices. One example is the so-called Newcomb problem (Nozick 1969). Suppose that you are given the choice between taking either both or only the first of two boxes containing money. Your choice will not affect the amount of money in either box. It is surely obvious in such a case that the rational choice is to take both boxes. However, it is possible that the probability that you will become rich, conditional on taking only the first box, is higher than the probability that you will become rich, conditional on taking both. Suppose that you know that the second box contains only one dollar. Now suppose that a team of brilliant psychologists have been studying your behavior for years, and they have put $1 million in the first box if and only if they have predicted that you will take only one box. Let's suppose that their prediction (in either case) has a 90% chance of being accurate. In such a situation, the probability that you will gain $1 million conditional on taking only the first box is much higher than the probability that you will gain $1 million conditional on taking both boxes. Your conditional expected utility for taking only the first box is about $900,000, while the conditional expected utility for taking both boxes is at most $101,000. Nonetheless, it seems crazy to leave the second box behind, since you don't cause any money to appear in the first box by not taking the second.
27
Causation: A Relation between Things or Truths?
We can now turn to questions about the nature of causation. We have talked about causes and effects as ‘things’, but what sort of things? Is causation a relation between things, like being next to or being taller than, or is it something else entirely? Let's look at a simple example:
(1) Mary's kicking the ball caused the ball to enter the goal.
There is another way to think about causal statements. We could rewrite (1) as (2):
(2) The ball entered the goal because Mary kicked it.
(2) seems to express pretty much the same thing as (1). In (2), there is no verb or preposition corresponding to causation. Instead, we have the word ‘because’, which joins two complete sentences into one compound sentence. (2) might suggest that causation is really a logical relation of some kind between two statements, something like the relations of conjunction (corresponding to the word ‘and’) or conditionality (corresponding to the words ‘if’ and ‘then’). Compare (2) with (3) and (4):
(3) The ball entered the goal if Mary kicked it.
(4) The ball entered the goal, and Mary kicked it.
We're not suggesting that (3) or (4) come close to saying the same thing as (2). We're simply asking you to pay attention to the logical form of (2), (3), and (4). None of us are tempted to suppose that the ‘and’ in (4) refers to some kind of relation between the ball's entering the goal and Mary's kicking it. Instead, we naturally believe that there is some relation between the truth or proposition expressed by (4) and the truths or propositions expressed by (5) and (6):
(5) Mary kicked the ball.
(6) The ball entered the goal.
Perhaps (2) has a similar relation to (5) and (6). Here is a plausible idea: (2) is true when it's the case that the truth of (6) can be correctly explained in a certain way in terms of the truth of (5).