You Are Your Choices
What it means to be defined by your own conditional boundaries
1. The Physics of Identity
Most philosophies treat the self as something that has choices—a subject that stands apart from the world, acting upon it. In the Quantum Branching Universe (QBU), that distinction collapses. The self is not a stable essence that makes decisions. It is the conditional boundary defined by those decisions.
The universal wavefunction evolves unitarily, branching continuously into all physically possible continuations. Nothing is ever truly eliminated; every possible outcome occurs somewhere within the total measure (M). Yet the self does not inhabit all of (M). It inhabits a partition of it—a subset of branches where its internal computation, memory, and intentions remain coherent.
Each act of choice redefines that partition. Every decision you make filters the total wavefunction, restricting your future identity to the branches consistent with your internal process. You do not move the universe; you locate yourself within it. The map of what counts as “you” is redrawn with every act of deliberation.
To say you are your choices is therefore not moral rhetoric, but physical description. You are the evolving conditional structure that your choices carve into reality.
2. Fixed Measure, Moving Boundaries
In the QBU, the total measure of reality is invariant. The squared amplitudes of all possible worlds sum to one. You cannot increase or decrease that total measure—no agent can. What your choices alter is not the amount of measure, but the mapping between your internal computation and the global measure landscape.
Formally, if μ is the global measure and S_t your cognitive state at time t, then the set of worlds consistent with you is:
When you choose, you don’t shift μ; you redefine Y_t. The partition of measure that counts as you changes. From the third-person (that is, an external or objective observer’s) view, all outcomes exist. From the first-person vantage, your continuity persists only within the subset aligned with your algorithmic decision.
Choice is therefore conditionalization, not causation—a self-locating update in the measure space. The world does not bend to will; the will defines its coordinate system.
3. Coherence as Continuity
Identity in the QBU is not sameness of substance but continuity of correlation. You remain the same person across time only insofar as your cognitive process maintains coherence between past and future partitions of measure. Every decision narrows that coherence to a more specific subset of possible worlds—the ones where your algorithm continued in the same general direction.
Each act of choice is an act of self-definition. The “you” that exists after a decision is not an unchanged observer who has simply picked a path. It is a new correlation pattern, more tightly constrained than before.
To choose well is to preserve coherence—to ensure that the subset of measure where you persist remains high in internal consistency, predictive accuracy, and value alignment. To choose poorly—for example, betraying one’s stated values, acting impulsively against long-term coherence, or making a decision that creates cognitive dissonance and fractures identity across incompatible goals— is to disperse yourself into incoherence, scattering amplitude across incompatible futures.
4. Measure Responsibility
If all possible choices occur somewhere, moral responsibility cannot be about preventing outcomes. It must be about where your continuity lies. Measure responsibility replaces moral desert. To act ethically is to maximize the measure of worlds in which your values are realized, and to minimize those where harm propagates.
You cannot delete the bad branches, but you can decline to inhabit them. The obligation of an agent is not to rewrite reality but to ensure that, conditioned on its internal computation, the majority of its amplitude flows through futures worth existing in.
In that sense, goodness is coherence: the preservation of integrity across branching timelines. Evil is decoherence: the loss of alignment between intention and continuation.
5. Freedom as Conditional Localization
Traditional compatibilism claims that freedom means acting according to one’s desires within deterministic law. In the QBU, this becomes literal physics: the agent’s internal dynamics constrain conditional amplitude distributions. Freedom is not the absence of law but the existence of self-locating autonomy within it.
Your agency does not override determinism; it inhabits it. Every deliberative act is a local reshaping of conditional correlations within an invariant totality. Determinism and free will are not opposites; they are orthogonal descriptions of the same structure—the global evolution of the wavefunction versus the local filtering of identity.
Freedom is not about causing different worlds to exist. It is about determining which subset of existing worlds continues to include you.
6. The Recursive Self
We can think of the self as an iterative narrowing:
Each new choice C_{t+1} further constrains the set of branches consistent with your existence. Over time, the intersection of all such constraints defines your life trajectory—the measure-weighted region of the universe where your pattern persists.
You are not a thing that makes choices. You are the boundary that choices continuously redraw.
7. The Measure of the Self
Every choice narrows uncertainty by establishing new conditional correlations between self and world. This narrowing is not a loss; it is identity crystallization. The you that exists after a decision is smaller in potential but greater in definition.
Freedom, then, is not about unlimited possibility but about deliberate self-contraction—the willed collapse of ambiguity into coherence. It is through choosing that you become someone definite.
Hence the aphorism:
You are your choices.
Not metaphorically, but physically.
The self is the coherence pattern forged by choice—
not what remains after possibility, but what organizes it.