it is evident that "absolute motion" is not motion with reference to "unlimited Space," which would be the same as motion without a moving; but is motion with reference to that point fixed in Space, around which all things revolve, but which is itself at perfect rest. "Another insuperable difficulty presents itself, when we contemplate the transfer of Motion." Motion is simply the moving of a body, and _cannot be transferred_. The _force_ which causes the motion is what is transferred. All that can be said of motion is, that it is, that it increases, that it diminishes, that it ceases. If the moving body impinges upon another moving body, and causes it to move, it is not motion that is transferred, but the force which causes the motion. The motion in the impinging body is diminished, and a new motion is begun in the body which was at rest. Again it is asked: "In what respect does a body after impact differ from itself before impact?" And further on: "The motion you say has been communicated. But how? What has been communicated? The striking body has not transferred a _thing_ to the body struck; and it is equally out of the question to say that it has transferred an _attribute_." Observe now that a somewhat is unquestionably communicated; and the question is:--What is it? Query. Does Mr Spencer mean to comprehend the Universe in "thing" and "attribute"? He would seem to. If he does, he gives a decision by assertion without explanation or proof, which involves the very question at issue, which is, Is the somewhat transferred a "thing" or an "attribute"; and a decision directly contrary to the acknowledgment that a somewhat has been communicated? On the above-named hypothesis his statement should be as follows: A somewhat has been communicated. "Thing" and "attribute" comprise all the Universe. Neither a thing, nor an attribute has been communicated, _i. e._ no somewhat has been communicated; which contradicts the evidence and the acknowledgment. If on the other hand Mr. Spencer means that "thing" and "attribute" comprise only a part of the Universe, then the question is not fairly met. It may be more convenient for the moment to conclude the Universe in the two terms thing and attribute; and then, as attribute is essential to the object it qualifies, and so cannot be communicated, it will follow that a thing has been communicated. This thing we call force. It is not in hand now to inquire what force is. It is manifest to the Sense that the body is in a different state after impact, than it was before. Something has been put into the body, which, though not directly appreciable to the Sense, is indirectly appreciable by the results, and which is as real an addition as water is to a bowl, when poured in. Before the impact the body was destitute of that kind of force--motor force would be a convenient term--which tended to move it. After the impact a sufficiency of that force was present to produce the motion.