If we had not direct proof, analogy would lead us to conclude, that no change could take place, in parts of so much sensibility as the muscles, without a change of feeling; in particular, that a {42} distinguishable feeling must attend every contraction, and relaxation. We have proof that there is such a feeling, because intimation is conveyed to the mind that the relaxation or contraction is made. I will, to move my arm; and though I observe the motion by none of my senses, I know that the motion is made. The feeling that attends the motion has existed. Yet so complete is my habit of attending only to the motion, and not to the feeling, that no attention can make me distinctly sensible that I have it. Nay, there are some muscles of the body in constant and vehement action, as the heart, of the feelings attendant upon the action of which we seem to have no cognisance at all. That this is no argument against the existence of those feelings, will be made apparent, by the subsequent explanation of other phenomena, in which the existence of certain feelings, and an acquired incapacity of attending to them, are out of dispute.[15] [Editor's footnote 15: The paradox, of feelings which we have no cognisance of--feelings which are not felt--will be discussed at large in a future note.--_Ed._] In most cases of the muscular feelings, there is not only that obscurity, of which we have immediately spoken, but great complexity; as several muscles almost always act together; in many of the common actions of the body, a great number. The result of these complex feelings is often sufficiently perceptible, though the feelings, separately, can hardly be made objects of attention. The unpleasant feeling of fatigue, in part at least a muscular feeling, is one of those results. The pleasure which almost all the more perfect animals, especially the {43} young, appear to feel, in even violent exercise, may be regarded as another. The restlessness of a healthy child; the uneasiness in confinement, the delight in the activity of freedom, which so strongly distinguish the vigorous schoolboy; seem to indicate, both a painful state of the muscular system in rest, and a pleasurable state of it in action. Who has not remarked the playful activity of the kitten and the puppy? The delight of the dog, on being permitted to take exercise with his master, extends through the greater part of his life. One of the cases in which the feeling of muscular action seems the most capable of being attended to, is the pleasure accompanying the act of stretching, which most animals perform in drowsiness, or after sleep.