considerations govern the distribution of pains relative to the other organs and senses of the body.
Again, we may note how pain is distributed with reference to its function as a warning against extraordinary influences. Relative to any bodily organ, its ordinary influences are those to which it has been developed; only the extraordinary are dangerous to that function. The ordinary course of blood circulation occasions no pain, but where there is congestion, there will be abnormal tension of tissue and consequent stimulation of the pain nerves terminating therein; terminating there for the purpose of warning against the dangers of disturbed circulation. An unusual blow causes pain; at first by concussion, afterwards by reason of bruised and congested tissue. A cut or tear exposes to mechanical irritation nerve ends which were before protected from such. Unusual heat or cold causes pain, as we hope to show, by unusual expansion or contraction of certain tissues in the skin. The whole system of pain nerves is an adjustment to the working equilibrium of our body. In places not usually disturbed, and where therefore they would be in the way, there they are not found. In places where violence or a disruption of the normal course of things is most imminent, there they are found. It would be difficult, we think, to account for the distribution of our pains in any similar manner upon the doctrine of their being inseparable qualia of other sensations.
It is common that a definite stimulation will at one time cause a certain sensation without pain, and at other times apparently cause precisely similar sensations with varying degrees of pain. Even the same absolute rise of temperature may occasion an increase of warmth feeling, now with an increase and again with a decrease of pain. Lotze has struggled with this inconstant relationship of pain and pleasure 'attributes' to the physical causes of the sensations to which he supposed them to belong. Yet upon any conceivable relationship of mind to physical basis, it seems as incomprehensible as ever how any sensation and an inseparable quale, both dependent simultaneously on the same identical influence, could thus sometimes the one
