This is a sequel to my previous post on determinism, free will and the existence of choice. Here I want to consider the semantics of the word “choice” from the perspective of lexical semantics generally. I will focus on the concept of a natural kind as formulated by Kripke, Putnam and Donnellan and which I encountered long ago in the introduction to the volume naming necessity and natural kinds.
The basic idea is that a word like “gold” or “lemon” is used meaningfully without any precise definition. There is a substance that we call gold and the existence of gold was known, and gold was correctly referred to, long before the acceptance of the atomic theory. Similarly one can meaningfully refer to “lemons” or “dogs” without knowing all the scientific facts and criteria that might be used in attempting to give a precise definition. A term which is used meaningfully, and for practical purposes does have a well defined referent, but where the detailed nature of the referent is unknown, is called a natural kind term.
Of course we can scientifically investigate the nature of gold or lemons. This does not mean that the referent can be changed. The term gold had a well defined referent in roman times and it would be scientific folly to investigate the nature of gold by changing the meaning (or referent) of the term.
Now the issue here is whether the term “choice”, like the term “gold”, has a meaning by virtue of its colloquial usage. To quote Wittgenstein, the meaning is the use. It would be scientific folly to study the nature of “choice” by redefining the word to mean something else. In particular, consider the claim that a deterministic computer does not have choice. One should recognize that when we talk about choices we are referring to something, just as the word “gold” refers to something. I claim that statements about the nature of choice can be true or false in the same way that statements about the nature of gold can be true or false. Furthermore, I claim that the statement that a deterministic computer cannot have choice is scientifically false in the same way that the statement that gold is a compound (like salt) is scientifically false. Does alphago make choices?
But if “choice”, like “gold”, is a natural kind term, what are choices really? The notion of choice seems intimately related to the computational process of decision making. Choices are the options considered in decision making. The notion of choice, or option, seems central to decision theory and central to the understanding of any decision making process whether or not that process is truly stochastic or is classically deterministic. The sentence “I decided to cancel the interview” seems to have a clear (if colloquial) meaning concerning some internal cognitive decision making process. The statement that an option existed and a decision was made seems perfectly compatible with a deterministic decision making process (as in a chess program).
Furthermore, whatever choices are, it seems that a sentence of the form “x was an option” has truth conditions — it can be true in some situations and not in others. The truth conditions may be complex and subtle, but the truth conditions, whatever they are, seem orthogonal to the issue of whether the decision making computation is deterministic.
It seems to me that “being free to choose” cannot be distinguished from “having options”. The deterministic chess program does have options — the set of legal moves exists and defines the options. We humans largely understand when we “have options” which we appropriately take to be synonymous with “being free to choose”. These words refer to something real just as “gold” refers to something real.
The truth conditions of “x was an option” seem related to the truth conditions of counterfactuals such as “if I had chosen to do x then y would have happen”. Such statements have clear meanings in the case of formal games. Such statements presumably also have truth conditions in normal human circumstances.
Choices are, by definition, the things people refer to when they talk about choices and options. We can investigate what these things (choices) are, but we should avoid trying to redefine the referent of this natural kind term. The meaning is the use.
Machine Thoughts 