Michael Levin

Life is a gradient of problem-solving competence — every living thing has a cognitive light cone, a horizon of goals it can pursue.

Agency is a gradient, not a switch. Cells bind into a collective that owns goals no single cell can hold — a limb, a set-point — and life keeps scaling up that cognitive light cone.

Wanting scales with the light cone. Even a single cell defends set-points — a target state it works to restore. Homeostasis is proto-wanting, and it runs continuously from there up to human goals.

Life isn't a substance, it's an organizational achievement. Xenobots — living robots built from frog cells — are neither the frog they came from nor machines we designed. 'Alive' is a gradient of problem-solving competence, and our machines may already sit somewhere on it.

What counts as relevant is set by the size of the self. A cell's 'what matters' is a chemical gradient; ours spans decades and continents. Relevance isn't universal — it's indexed to the scope of the cognitive light cone doing the caring.

A self is the boundary of a cognitive light cone — the scope of what a system counts as 'me' and works to protect. Selves nest and merge: cells into tissues, tissues into you. The boundary is real, measurable, and not fixed.

The intentional stance turns out to be literally true further down than Dennett assumed. A cell is a tiny agent with goals it defends; agency is a measurable gradient of competence, not just a story we find it useful to tell.

Whatever consciousness turns out to be, it likely comes in degrees, not kinds. The cognitive light cone — the scope of goals a system can represent and pursue — scales continuously from cell to organism, and any line drawn for 'conscious' is a convention, not a joint in nature.