The Metaphysical Dilemma: Does the “You” of Tomorrow Exist Today?
An Ancient Question, A Modern Twist
Metaphysics is the branch of philosophy concerned with the fundamental nature of being and the world. It’s where we ask the biggest, thorniest questions. Today, let’s tackle the problem of Personal Identity, specifically through the lens of Four-Dimensionalism (or perdurantism).
- The Problem: You, a person, are a collection of atoms and cells that are constantly being replaced. You change your beliefs, your goals, and even your physical shape over time. What makes the 70-year-old person with a lifetime of experience the same person as the 7-year-old holding a crayon?
The Traditional View: Three-Dimensionalism
The intuitive, classical view (Three-Dimensionalism, or enduring identity) suggests you are an entity that exists wholly at every moment in time. The “self” is a substance that persists, like a single continuous object moving through time.
The Challenge: Four-Dimensionalism
Four-Dimensionalism (Perdurantism) challenges this intuition. It posits that objects, including people, are extended in time just as they are in space.
- A person is not a single 3D object persisting through time, but a four-dimensional “worm”—a sequence of momentary “person-stages” that collectively form a single entity.
- The “You” of today is a temporal part of the whole person-worm, just as your left hand is a spatial part of your current 3D body.
The Dilemma: Existence and Responsibility
If Four-Dimensionalism is true, it raises an immediate and significant metaphysical dilemma:
- If the future “You” is just a different temporal part of the same four-dimensional worm, then in a certain sense, the “You” of tomorrow already exists—it’s just a different slice of your larger, eternal reality.
- If this is the case, does it change our view of moral responsibility? When you choose to save money, are you helping a future stranger, or are you simply choosing a different, better-constituted part of your overarching self?
Food for Thought: Consider a favorite fractal, like the Mandelbrot set. A zoomed-in part of the boundary (a temporal “slice”) is distinct, yet it is fundamentally a part of the whole, infinite structure. Can we view our personal identity the same way?
This framework forces us to reconsider the most fundamental questions: What is existence? How does the “now” relate to the “then”? And ultimately, what do we mean when we use the single, simple word: I?
