Dover's cliffs call to mind the Roman invasion; the Battle of Britain; our proximity to, yet difference from, mainland Europe; and international trade and exploration, both fair and exploitative.
The mark of a mature, psychologically healthy mind is indeed the ability to live with uncertainty and ambiguity, but only as much as there really is. Uncertainty is no virtue when the facts are clear, and ambiguity is mere obfuscation when more precise terms are applicable.
The idea that the mind can extend even beyond the body is an intriguing one, and is bound to become more pressing as we increasingly develop technologies that augment our natural abilities.