Darwin believed, on the contrary, that it was a phenomenon produced by means of the will. I consider it advisable to quote here in full the explanation which he gives of blushing, as no other naturalist made it the object of such special study, and because his hypothesis is at variance with the facts of my observation. 'Men and women, and especially the young, have always valued, in a high degree, their personal appearance, and have likewise regarded the appearance of others. The face has been the chief object of attention, though, when man aboriginally went naked, the whole surface of his body would have been attended to. Our self-attention is excited almost exclusively by the opinion of others, for no person living in absolute solitude would care about his appearance. Everyone feels blame more acutely than praise. Now, whenever we know, or suppose, that others are depreciating our personal appearance, our attention is strongly drawn toward ourselves, more especially to our faces. The probable effect of this will be, as has just been explained, to excite into activity that part of the sensorium which receives the sensory nerves of the face; and this will react through the vaso-motor system on the facial capillaries. By frequent reiteration during numberless generations, the process will have become so habitual, in association with the belief that others are thinking of us, that even a suspicion of their depreciation suffices to relax the capillaries, without any conscious thought about our faces. With some sensitive persons it is enough even to notice their dress to produce the same effect. Through the force, also, of association and inheritance our capillaries are relaxed, whenever we know, or imagine, that anyone is blaming, though in silence, our actions, thoughts, or character; and, again, when we are highly praised.’ 'On this hypothesis we can understand how it is that the face blushes more than any other part of the body.’ 'Of all expressions, blushing seems to be the most strictly human.’ 'But it does not seem possible that any animal, until its mental powers had been developed to an equal or nearly equal degree with those of man, would have closely considered and been sensitive about its own personal appearance. Therefore we may conclude that blushing originated at a very late period in the long line of our descent.’[2] [2] Charles Darwin: _The Expression of the Emotions_, pp. 345 and 364. London, 1872. I hold that this explanation of blushing is no longer tenable, and I think that perhaps Darwin himself would have accepted mine, since it seems to me truer, more in correspondence with the theory of evolution, more Darwinian, if I may be allowed the expression.