Full Idea
What may be called the Kantian wing and the Surrealist wing of existentialism may be distinguished by the degree of their interest in reasons for action, which diminishes to nothing at the Surrealist end.
Gist of Idea
Kantian existentialists care greatly for reasons for action, whereas Surrealists care nothing
Source
Iris Murdoch (The Sovereignty of Good [1970], I)
Book Reference
Murdoch,Iris: 'The Sovereignty of Good' [RKP 1974], p.35
A Reaction
Presumably for all existentialists moral decisions are the most important aspect of life, since they define what you are, but the Surrealist wing seem to be nihilists about that, so they barely count as existentialists. For them life is sleepwalking.