Man vs self is conflict where a character is their own enemy.
It usually has exists when there is an internal conflict within the character. It can also be the primary conflict the character has to overcome.
From Oscar Wilde's <em>The Picture of Dorian Gray </em>, there is conflict of man versus self as the character refuses to bare his soul to the world, resists putting himself under self examination because he doesn't want to let his heart put under a microscope as it would reveal too much of himself.
