“The hedgehog’s dilemma, or sometimes the porcupine dilemma, is a metaphor about the challenges of human intimacy. It describes a situation in which a group of hedgehogs seek to move close to one another to share heat during cold weather. They must remain apart, however, as they cannot avoid hurting one another with their sharp spines. Though they all share the intention of a close reciprocal relationship, this may not occur, for reasons they cannot avoid.
Arthur Schopenhauer conceived this metaphor to describe what he considers to be the state of the individual in relation to others in society. The hedgehog’s dilemma suggests that despite goodwill, human intimacy cannot occur without substantial mutual harm, and what results is cautious behavior and weak relationships. With the hedgehog’s dilemma, one is recommended to use moderation in affairs with others both because of self-interest, as well as out of consideration for others. The hedgehog’s dilemma is used to explain self-imposed isolation.” – Wikipedia