Knowing what we do about mental extensions and how they work, we are now able to assemble the conditions for intelligence, even brilliance. In this book we’ve looked intently at one extension at a time: interoceptive signals, movements, and gestures; natural spaces, built spaces, and the “space of ideas”; experts, peers, and groups. But evidence suggests that extensions are most powerful when they are employed in combination, incorporated into mental routines that draw on the full range of extra-neural resources we have at hand.
