The Case Against Reality: Why Evolution Hid the Truth from Our Eyes

by Donald D. Hoffman

I take my perceptions seriously, but not literally.

Realism is the claim that physical objects have definite values of physical properties—such as position, momentum, spin, charge, and polarization—even when unobserved. Locality is the claim that physical objects cannot influence each other faster than the speed of light. Local realism asserts that both realism and locality are true.

So is another theorem that follows from quantum theory and makes no assumption about locality. It was proven by Bell, in 1966, and by Simon Kochen and Ernst Specker, in 1967, and is called the Kochen-Specker (KS) Theorem. It says that no property, such as position or spin, has a definite value that is independent of how it is measured.9 The opposite claim, that a property can have a definite value that is independent of how it is measured, is called “noncontextual realism.” The KS Theorem says that noncontextual realism is false.

In sum, a conscious agent has experiences and actions, which are menus (measurable spaces). It perceives, decides, and acts, which are conditional changes (Markovian kernels). And it counts how many experiences it has had. That’s the entire definition of a conscious agent. It is, a mathematician would assure you, a simple bit of math.