Seven types of argument

We treat things differently based on how we classify them.

For example, if you are blind, then in many countries you may be eligible for a range of benefits and support services, such as disability payments, housing, free audiobooks and so on.

But what does it mean to be blind?

Does it mean you have absolutely no vision at all?

There are many people in the world who have some vision, but not enough that they can navigate the world the way an average-sighted person does. Are they blind or not blind?

Here a woman called Sarah describes what she can see:

Is Sarah blind?

Not if you define blindness as "having absolutely no vision".

But is she blind enough to be eligible for the same benefits and services that a completely blind person is entitled to?

How blind is "blind enough"?

This is a really important question! The answer determines whether or not a person gets access to job support, free transport, free audiobooks and so on.

And to answer it, most countries have a category called "legally blind" with clear, objective, measurable criteria.

Here's the Australian standard. Can you see the two criteria?

What we've been talking about here is a definitional argument.

• In a definitional argument, we have categories with defined membership criteria.
• We classify something (or someone) as a member of a category if it meets the membership criteria (using criteria & match reasoning).

"Completely blind" and "legally blind" are categories. In Australia:

• Completely blind is defined as:
  • No vision at all.
• Legally blind is defined as either:
  • 6/60 distance vision (or worse), or
  • 20-degree field of vision (or worse).
• A person is classified as a member of either of these categories if they meet the criteria.

One good feature of the criteria for legal blindness is they are objective; it's pretty clear who is or is not a member of the category.

But not everything can be defined so objectively:

• What is a sport?
• What is a war?
• What is a drug?
• What is a disability?

Even something as straightforward as "complete blindness" turns out to be trickier than you'd think.

Daniel Kish has no eyes, but is he blind? (Wikipedia)

For example, Daniel Kish is "completely blind" because he literally has no eyes—they were removed when he was only 1 year old (because of eye cancer).

But he doesn't actually think of himself as "blind". Here is a snippet from a radio interview where he leads a journalist through the woods:

Daniel is famous for navigating by echolocation: he clicks his tongue and listens to sound as it reflects off surfaces around him, like a bat.

From that sound information, he constructs a picture of the world (notice how he literally uses words related to sight):

Daniel is completely blind, but because he builds a spatial model of the world around him using echolocation, he thinks of himself as "seeing".

So what does it actually mean to "see"?

That might sound like a really abstract, philosophical question, but like we said at the beginning of this page: we treat people and things differently based on how we classify them.

So how we define our categories and criteria is really important, as is how we figure out who or what meets the criteria to belong in a given category:

• Is a terrorist attack an act of war?
• Are pain medications a drug?
• Are esports players athletes?

As we said, some of these definitional questions can be hotly contested, but they have big implications.

To recap

• Definitional arguments are about classification and identity:
  • Is this person blind?
  • Is this show news or entertainment?
  • Is this virus outbreak a pandemic?
• They're not about whether or not something exists; they're about how we categorise it.
• Every category is defined by membership criteria and definitional arguments compare features to criteria and see where they match.
• Definitional arguments are important because "what it is" or "who they are" determines how we treat it or them.