Just semantics?

In a recent article on free will I argued that there are, very broadly speaking, two candidate meanings for the term "free will". I ended the article by asking: which of the two definitions is better? But what does it even mean for one definition of a term to be better than another? And isn't this, as they say, "just semantics"? 

Not just academic.

This question goes way beyond discussions of free will of course. And it's not just academic, it features heavily in some of today's most hot button issues. Take gay marriage for example. The core argument conservatives are putting forward is specifically about the definition of the concept "marriage". They are saying that the correct definition of  "marriage" is that it's between a man and a woman. They claim that supporters of gay marriage are trying to redefine marriage.

Or how about abortion. Does human life begin at conception? That crucial question in the debate is about the definitions of  "human" and "life". Is a fetus a baby? Is it a person? Is it a part of a woman's body? These questions are not about the biology of what's going on but about proper definitions of terms like "baby", "person", and "body".

Or take the hottest of the hot button topics, trans issues. Some say that "a trans woman is a woman", others disagree. What is the disagreement exactly? It's about what makes a woman a woman, i.e. the definition of "woman": is it determined by one's biology, one's sincere self-identification, or something else?

We are not going to discuss these volatile questions here. But I hope you see how much hinges on being able to adjudicate definitional questions. So how do we do that?

Can you feed fish to free will?

Let's start with a view that I've heard many people express: you are free to define terms however you want as long as you make it clear what you are talking about. Of course on a certain level that's trivially true - you won't be arrested for doing that. But consider this example: what if I said that my definition of "free will" is that it's a penguin wearing a tophat? 

Clearly I have just slapped the label "free will" on something that has nothing to do with what anybody means by "free will" in English. Is there anything wrong with that? Well, I am not breaking the law by doing that. But it would be silly of me to insist that I am contributing something useful to the dialogue about free will, if I start sharing insights like "those free wills look really stylish with their little tophats, I'd like to pet one and give it some fish." I am just not speaking English at that point. 

So one way a particular definition for a term can be "bad" is if it doesn't correspond to what people mean when they use the term. Calling a dog a chair is silly and confusing, even if you make it clear that's what you are doing. If you do that, you are basically inventing your own language and trying to speak it to others. So one way we could adjudicate between two competing definitions is if one of them is like calling a dog a chair.

Let's speak English.

But that's not the only way one definition can be better than another. Consider another example: if you remove three legs from a chair is it still a chair? Some people would call it a chair and some wouldn't (if you disagree you can probably come up with your own example of some entity which many people would describe with a particular term but many others wouldn't). The point is that reasonable people who speak the same language often assign slightly different meanings to terms, even common everyday words.

What's the difference between applying the term "chair" to a dog versus applying it to a chair with three legs removed? Basically in the first case you are just not speaking English, but in the second you are. English has some degree of flexibility to it but the flexibility has its limits. The range of flexibility is determined by the native speakers of the language - roughly speaking if enough reasonable native speakers would apply the term "chair" to some entity then we'll say it's a legitimate use of the term.

Of course there is no sharp boundary between "enough native speakers" and "not enough", legitimate use vs illegitimate. Like most things, it's a matter of degree. You can choose your own threshold for how widespread a particular use of a term has to be for you to call it legitimate, just as you can decide - within reason - a height threshold for you to call someone tall. I'll say if over 15% of native speakers would use a term in a particular way, I'll call that a legitimate use of the term. 

Judging between legitimate definitions.

So, as we said before, one way a definition of a term can be problematic is if it's simply illegitimate, but what could be another way? Suppose we have two possible definitions of a term such as "marriage" or "free will", one consistent with how 42% of people would use the term, the other consistent with 49% of people. Presumably we don't want to accuse either group of not speaking English, so, besides robotically comparing percentages, what other criteria can we use to judge between these definitions?

The general idea is that a particular use of the term may be widespread but in some way defective. Let me give a few examples.

Example 1. Vacuous or trivial meaning.

Some people take the word "God" to refer to almost anything that could potentially underlie reality, even just laws of nature. Even if this use of the term were somewhat widespread, we could still argue that such a definition strips any interesting content from the concept. It's utterly vague and renders statements like "I believe in God" completely vacuous.

Example 2. Indeterminate meaning.

Sometimes a number of people use a term in a way that leaves it indiscernible what meaning is actually assigned to it. An example that springs to mind is the word "vibrations". Some people say things like:

Our brain and heart emits energy (vibrations), which can have big impact on our surroundings.

We all feel and respond, to each others’ vibrations, even if we’re not aware of it.

It is, as far as I can tell, indeterminate whether the term refers to some entity subject to regular laws of physics or maybe a supernatural entity, something objectively existing or just a feeling or impression, something reducible to common, well-known things or something distinctly apart from them, something actually vibrating or not.

Example 3. Incoherent or confusing meaning.

Sometimes the requirements imposed by people on a term just don't make sense. For example, many people's conception of God includes the following essential characteristics:

• Absolute goodness
• Omnipotence 

Under a straightforward interpretation of these characteristics, such a conception of God is incoherent. For suppose there are two possible choices of action: one good, one evil. Is God able to perform the evil one? Under a straightforward interpretation of "absolute goodness" the answer is no, but under a common understanding of "omnipotence" the answer is yes.

That doesn't of course mean that I've just disproved the Christian God, a sophisticated theologian can come up with a theory of these two characteristics that would remove the incoherence. But the point is that many people don't have such a theory, and operate with an incoherent notion of God.

Summary.

I have argued that the question of adjudicating among different meanings of a term is not a vacuous exercise in "just semantics". This question plays a vital role in many hot button issues being discussed today. I have suggested two basic ways a definition of a term can be judged inadequate: 

1. It might not be legitimate, if it's like calling a dog a chair. Using a term this way could be described as speaking one's own language instead of English.
2. It might be legitimate but in some way defective. Within English there could be competing definitions for a term, but some of them can suffer from various deficiencies. They could be vacuous, indeterminate, or incoherent, though this doesn't exhaust the list of undesirable properties.