But when a blush is excited in solitude, the cause almost always relates to the thoughts of others about us—to acts done in their presence, or suspected by them; or again when we reflect what others would have thought of us had they known of the act. Nevertheless one or two of my informants believe that they have blushed from shame at acts in no way relating to others. If this be so, we must attribute the result to the force of inveterate habit and association, under a state of mind closely analogous to that which ordinarily excites a blush; nor need we feel surprise at this, as even sympathy with another person who commits a flagrant breach of etiquette is believed, as we have just seen, sometimes to cause a blush. Finally, then, I conclude that blushing,—whether due to shyness—to shame for a real crime—to shame from a breach of the laws of etiquette—to modesty from humility—to modesty from an indelicacy—depends in all cases on the same principle; this principle being a sensitive regard for the opinion, more particularly for the depreciation of others, primarily in relation to our personal appearance, especially of our faces; and secondarily, through the force of association and habit, in relation to the opinion of others on our conduct. _Theory of Blushing_.—We have now to consider, why should the thought that others are thinking about us affect our capillary circulation? Sir C. Bell insists[1331] that blushing “is a provision for expression, as may be inferred from the colour extending only to the surface of the face, neck, and breast, the parts most exposed. It is not acquired; it is from the beginning.” Dr. Burgess believes that it was designed by the Creator in “order that the soul might have sovereign power of displaying in the cheeks the various internal emotions of the moral feelings;” so as to serve as a check on ourselves, and as a sign to others, that we were violating rules which ought to be held sacred. Gratiolet merely remarks,—“Or, comme il est dans l’ordre de la nature que l’être social le plus intelligent soit aussi le plus intelligible, cette faculté de rougeur et de pâleur qui distingue l’homme, est un signe naturel de sa haute perfection.” The belief that blushing was SPECIALLY designed by the Creator is opposed to the general theory of evolution, which is now so largely accepted; but it forms no part of my duty here to argue on the general question. Those who believe in design, will find it difficult to account for shyness being the most frequent and efficient of all the causes of blushing, as it makes the blusher to suffer and the beholder uncomfortable, without being of the least service to either of them. They will also find it difficult to account for negroes and other dark-coloured races blushing, in whom a change of colour in the skin is scarcely or not at all visible.