It needs to be discovered why the mentally ill person's “voices” do not resemble a crowded room with everyone talking at once. Instead, the voices keep themselves to one word expressed at a time.
I believe the answer is in the shape of the sphere of interest. In the mentally ill person that sphere is filled with both interest and exterest. The exterest is where the voices come from. It would seem that the ability to create a word in the mind is a property of the sphere shape, and just as it limits the mentally ill person himself to one word at a time, so too it limits the exterest to one word at a time, even though exterest is populated by many people's roving essential atoms.
This solution brings us to another puzzle. Why are voices so much more powerful than the mentally ill person's own thoughts? His own thoughts always recede in deference to voices. I believe the solution is in an effect i will call “mission”. Mission arises in numbers—numbers of people responsible for the effect of exterest. While normal people only have exterest in their medians, at the outer limits of their spheres of interest, and therefore mission is not great enough to be easily noticed, mentally ill people have exterest throughout their spheres of interest, and therefore mission is pronounced. It carries the impulsiveness of the species' will to survive, a will which any one person does not individually shape, no matter whether ill or normal.