The Lives of a Cell by Lewis Thomas

We pass thoughts around, from mind to mind, so compulsively and with such speed that the brains of mankind often appear, functionally, to be undergoing fusion . . . Or perhaps we are only at the beginning of learning to use the system, with almost all our evolution as a species still ahead of us. Maybe the thoughts we generate today and flick around from mind to mind are the primitive precursors of more complicated, polymerized structures that will come later, analogous to the prokaryotic cells that drifted through shallow pools in the early days of biological evolution. Later, when the time is right, there may be fusion and symbiosis among the bits, and then we will see eukaryotic thought, metazoans of thought, huge interliving coral shoals of thought . . . The mechanism is there [in the human brain], and there is no doubt that it is already capable of functioning.