A friend, therefore, is a sort of paradox in nature. I who...

A friend, therefore, is a sort of paradox in nature. I who alone am, I who see nothing in nature whose existence I can affirm with equal evidence to my own, behold now the semblance of my being, in all its height, variety, and curiosity, reiterated in a foreign form; so that a friend may well be reckoned the masterpiece of nature.