Suppose, for instance, a general receives a message containing a few words. He opens the paper, he reads it, and all on a sudden, his mind is in a tumult of excitement. What is it that produces the excitement? Is it any motion? Yes! In a certain sense, it is a motion: it is the reading of the paper. This is the cause. Yet not the reading as such excites his consternation. He might read other messages all the day long without any such an effect. Plainly, the causative element of the cause is not the reading, not the motions of which the reading consists, not the shape of the written characters and their combinations in groups, called words. It is something more subtle even than that. It is the significance of the writing. It is the meaning of the written characters. It is the purport that is attached to the word-symbols. The origin of mind accordingly introduces a factor which has nothing to do with mechanics; and the simplest psychical reflexes, including those physiological reflexes which we must suppose to have originated by conscious adaptation and then been submerged into unconsciousness, cannot be explained from mechanical or physical laws alone. SPONTANEITY. While we thus reject the conception of the mechanical philosophy and also of materialism, we do not say that there are motions either in the brain or anywhere else which form exceptions to the laws of mechanics. The laws of mechanics hold good for all motions. The laws of mechanics are formal laws: they do not explain why bodies gravitate; but they describe how they gravitate; and the latter is much more useful to know than the former. There is (as we conceive it) no deep secret in the problem why bodies gravitate; they gravitate because they possess a quality which attracts them to each other with a force directly as their masses and inversely as the squares of their distances. In a word, gravity is the intrinsic nature of masses, it is an inalienable part of their existence. Thus whenever bodies gravitate, we are confronted with an act of spontaneity. Attempts have been made to explain gravitation without the assumption of spontaneity, by the pressure of an atom-surrounding ether. But that only defers the question; for the spontaneity, in that case, would have to be placed in the ether. Whatever be the merits of the explanations of gravitation by a _vis a tergo_, we must recognise the fact that no motion can take place in the world, no pressure can be exercised, without there being somewhere some spontaneous something that moves or presses. Spontaneity is a universal feature of nature. Mr. Peirce uses the term “spontaneity” in a different sense from ours. He identifies spontaneity with absolute chance. He means by it the irregularities that arise without cause, thus producing departures from law. We call that action spontaneous which is not due to external influence but springs from the nature of the things in action.