Defining the Self: A Logical Exploration

Can you define yourself? Can you define your life? Can the answer be literal? What does logic have to do with any of that? As I discuss in Logic in the Wild, definitions serve as first principles of reasoning, alongside assumptions and axioms. Definitions are sometimes instrumental, for instance, in geometry, where there are no observable starting points. Instead, one typically defines what points, lines, and angles are, and then applies logic to unpack results in the form of theorems.

In science, there’s a clash between how the concept of mass is defined in Newtonian and relativistic physics—a clash that can be accommodated but that, without some coherence treatment, could lead to bad results. There are parts of science, however, where definitions matter little and can become a red herring for public debate, as when the definition of a planet was changed by a vote at a convention to demote Pluto from the status of a planet. While I don’t believe the new definition of a planet is justified or appropriate, it doesn’t matter whether we call Pluto a planet or not. It won’t affect our interest in studying it, the pictures we’ll take of it with the probes we send out, or anything besides what kids get to memorise in school and what models of the solar system look like at science fairs.

Now, where would a definition of the self belong on that spectrum? I don’t see how we could define a “self” as a first principle of reasoning like geometers define points or lines. Nor is it as insignificant as whether to call Pluto a planet or not. Is it, then, more like how mass is defined and treated in different scientific theories? Not really. For one, I wouldn’t claim that science has much to say in how we understand identity, the self, and presence in the world. It’s just not what it’s good at. But perhaps there’s something analogous that can help, namely that a definition is sometimes a way to categorise and articulate an important component. In science, a component of a theory, but in human existence, what life is and means for the you.

So, a definition is not there to bring you into existence but to help you articulate how you understand who you are and your presence in the world. And logic kicks in by guiding you in finding coherence in the way you articulate your life, perhaps in the narrative you give to understand your world, perhaps in a more direct way in identifying what makes you who you are. But of course, defining yourself or your life is more a metaphorical statement, something about establishing your presence in the world by owning your actions and your identity. Definition is then a much thicker concept that encapsulates a complex and rich understanding of who you are and your presence in the world. Even there, though, logic can still be there to guard coherence in the expression of your self.