Here we should notice a peculiar fact: that there are movements which are both essentially involuntary and yet confined to persons - to creatures with a self-conscious perspective. Smiles and blushes are the two most prominent examples. Milton puts the point finely in Paradise Lost: for smiles from Reason flow, To brute denied, and are of love the food. These physiognomic movements owe their rich intentionality to this involuntary character, for it is this which suggests that they show the other 'as he really is'. Hence they become the pivot and focus of our interpersonal responses, and of no response more than sexual desire. The voluntary smile is not a smile at all, but a kind of grimace which, while it may have its own species of sincerity--as in the smile of Royalty, which as it were pays lip-service to good nature -- is not esteemed as an expression of the soul. On the contrary, it is perceived as a mask, which conceals the 'real being' of the person who wears it. Smiling must be understood as a response to another person, to a thought or perception of his presence, and it has its own intentionality. To smile is to smile at something or someone, and hence when we see someone smiling in the street we think of him as 'smiling to himself, meaning that there is some hidden object of his present thought and feeling. The smile of love is a kind of intimate recognition and acceptance of the other's presence - an involuntary acknowledgement that his existence gives you pleasure. The smile of the beloved is not flesh, but a kind of stasis in the movement of the flesh. It is a paradigm of 'incarnation': of the other made flesh, and so transforming the flesh in which he is made. Thus the smile of Beatrice conveys her spiritual reality; Dante must be fortified in order to bear it, for to look at it is to look at the sun (Paradiso, XXIII, 47--8): tu hai vedute cose, che possente set fatto a sostener lo riso mio.