The motives of someone in a hypothetical Robinson Crusoe situation could scarcely be called desires since they would be entirely self-regarding. Desire proper only arises in a world of being-with, but since this is the world you always find yourself in, every motive is primarily social. The ideal of being true to your desire implicitly assumes that desire has an authentic form, free of mimesis, for example, and is thus subject to all the conundrums and epicycles of the ideal of authenticity.