Spirit

Spirit (lit. breath of life), in philosophy and theology is the Divine mind incarnating itself in the life of a man, and breathing in all he thinks and does, and so is as the life-principle of it; employed also to denote any active dominating and pervading principle of life inspired from any quarter whatever and coming to light in the conduct.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)