Every individual's ability to theorize is constrained on all sides. We need to think as a culture or as an organism in order to think well. Multiple perspectives, sometimes in irreconcilable formulations, are needed to get a decent picture of the world.
Almost like every individual is analogous to a single neuron, in a way. Except rather than trying to construct a conscious facsimile of reality as individual experience, we're trying to construct a conscious facsimile of reality as a theory shareable via language.