Involuntary expression of self
…a man is never so much represented to the perspective of another as when he blushes or laughs. The expression on a face is largely determined by involuntary movements; and yet it is the living picture of the perspective that ‘peers’ from it, and hence the true and dominant image of the ‘self’. Its glances, smiles and blushes are the involuntary marks of a self-conscious perception. These reveal the other’s perspective partly because he does not fully control them, and we desire him through them precisely when their movements are most involuntary—as in the closing of the eyes and the opening of the mouth in the kiss of passion.
Roger Scruton, Sexual Desire