No man is island

But how to connect to the continent? Is there any island shared by two?

On Aug 8, I just found the origin of 'No man is island'.
This is a quotation from John Donne (1572-1631). It appears in Devotions Upon Emergent Occasions, Meditation XVII:

All mankind is of one author, and is one volume; when one man dies, one chapter is not torn out of the book, but translated into a better language; and every chapter must be so translated...As therefore the bell that rings to a sermon, calls not upon the preacher only, but upon the congregation to come: so this bell calls us all: but how much more me, who am brought so near the door by this sickness....No man is an island, entire of itself...any man's death diminishes me, because I am involved in mankind; and therefore never send to know for whom the bell tolls; it tolls for thee.