Decisions as Predictions

Among acts of will, St. Thomas distinguishes intention and choice:

The movement of the will to the end and to the means can be considered in two ways. First, according as the will is moved to each of the aforesaid absolutely and in itself. And thus there are really two movements of the will to them. Secondly, it may be considered accordingly as the will is moved to the means for the sake of the end: and thus the movement of the will to the end and its movement to the means are one and the same thing. For when I say: “I wish to take medicine for the sake of health,” I signify no more than one movement of my will. And this is because the end is the reason for willing the means. Now the object, and that by reason of which it is an object, come under the same act; thus it is the same act of sight that perceives color and light, as stated above. And the same applies to the intellect; for if it consider principle and conclusion absolutely, it considers each by a distinct act; but when it assents to the conclusion on account of the principles, there is but one act of the intellect.

Choice is about the means, such as taking medicine in his example, while intention is about the end, as health in his example. This makes sense in terms of how we commonly use the terms. When we do speak of choosing an end, we are normally considering which of several alternative intermediate ends are better means towards an ultimate end. And thus we are “choosing,” not insofar as the thing is an end, but insofar as it is a means towards a greater end that we intend.

Discussing the human mind, we noted earlier that a thing often seems fairly simple when it is considered in general, but turns out to have a highly complex structure when considered in detail. The same thing will turn out to be the case if we attempt to consider the nature of these acts of will in detail.

Consider the hypothesis that both intention and choice consist basically in beliefs: intention would consist in the belief that one will in fact obtain a certain end, or at least that one will come as close to it as possible. Choice would consist in the belief that one will take, or that one is currently taking, a certain temporally immediate action for the sake of such an end. I will admit immediately that this hypothesis will not turn out to be entirely right, but as we shall see, the consideration will turn out to be useful.

First we will bring forward a number of considerations in favor of the hypothesis, and then, in another post, some criticisms of it.

First, in favor of the hypothesis, we should consider the fact that believing that one will take a certain course of action is virtually inseparable from deciding to take that course of action, and the two are not very clearly distinguishable at all. Suppose someone says, “I intend to take my vacation in Paris, but I believe that I will take it in Vienna instead.” On the face of it, this is nonsense. We might make sense of it by saying that the person really meant to say that he first decided to go to Paris, but then obstacles came up and he realizes that it will not be possible. But in that case, he also changes his decision: he now intends to go to Vienna. It is completely impossible that he currently intends to go to Paris, but fully believes that he will not go, and that he will go to Vienna instead.

Likewise, suppose someone says, “I haven’t yet decided where to take my vacation. But I am quite convinced that I am going to take it in Vienna.” Again, this is almost nonsensical: if he is convinced that he will go to Vienna, we would normally say that he has already made up his mind: it is not true that he has not decided yet. As in the previous case, we might be able to come up with circumstances where someone might say this or something like it. For example, if someone else is attempting to convince him to come to Paris, he might say that he has not yet decided, meaning that he is willing to think about it for a bit, but that he fully expects to end up going to Vienna. But in this case, it is more natural to say that his decision and his certainty that he will go to Vienna are proportional: the only sense in which he hasn’t decided yet, is to the degree that the thinks there is some chance that he will change his mind and go to Paris. Thus if there is no chance at all of that, then he is completely decided, while if he is somewhat unsure, his decision is not yet perfect but partial.

Both of the above cases would fit with the claim that a decision is simply a belief about what one is going to do, although they would not necessarily exclude the possibility that it is a separate thing, even if inseparably connected to the belief.

We can also consider beliefs and decisions as something known from their effects. I noted elsewhere that we recognize the nature of desire from its effect, namely from the fact that when we have a desire, we tend to bring about the thing we desire. Insofar as a decision is a rational desire, the same thing applies to decisions as to other kinds of desires. We would not know decisions as decisions, if we never did the things we have decided to do. Likewise, belief is a fairly abstract object, and it is at least plausible that we would come to know it from its more concrete effects.

Now consider the effects of the decision to go to Vienna, compared to the effects of the belief that you will go to Vienna. Both of them will result in you saying, “I am going to go to Vienna.” And if we look at belief as I suggested in the discussion to this post, namely more or less as treating something as a fact, then belief will have other consequences, such as buying a ticket for Vienna. For if you are treating it as a fact that you are going to go there, either you will buy a ticket, or you will give up the belief. In a similar way, if you have decided to go, either you will buy a ticket, or you will change your decision. So the effects of the belief and the effects of the decision seem to be entirely the same. If we know the thing from its effects, then, it seems we should consider the belief and the decision to be entirely the same.

There is an obvious objection here, but as I said the consideration of objections will come later.

Again, consider a situation where there are two roads, road A and road B, to your destination C. There is a fallen bridge along road B, so road B would not be a good route, while road A is a good route. It is reasonable for a third party who knows that you want to get to C and that you have considered the state of the roads, to conclude that you will take road A. But if this is reasonable for someone else, then it is reasonable for you: you know that you want to get to C, and you know that you have considered the state of the roads. So it is reasonable for you to conclude that you will take road A. Note that this is purely about belief: there was no need for an extra “decision” factor. The conclusion that you will factually take road A is a logical conclusion from the known situation. But now that you are convinced that you will take road A, there is no need for you to consider whether to take road A or road B; there is nothing to decide anymore. Everything is already decided as soon as you come to that conclusion, which is a matter of forming a belief. Once again, it seems as though your belief that you will take road A just is your decision, and there is nothing more to it.

Once again, there is an obvious objection, but it will have to wait until the next post.


2 thoughts on “Decisions as Predictions

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s