Upon the same principle, it is, that the particles of a pigment, when in contact, are more evident than when extended over an immense surface, or that a combination of pullies and one cord produce more evident motion than each of them, with separate cords, could separately. But it is unnecessary to accumulate illustrations—the principle pervades all nature, and every natural operation illustrates it. Nor do we merely find evident sensibility thus produced by the various arrangements of matter: it is implicitly dependent on all the changes of bodies, and is identified with their motions, by being suspended whenever these are suspended. Of this, the hybernation of animals, the winter state of most plants, the state of the embryo in utero or in ovo, of the chrysalids of insects, the nymphs of worms, and the seeds of plants, afford examples. Nor is this all: but evident sensibility may be produced and destroyed at pleasure by a mere alteration in the arrangement of the particles of one and the same body; as in the wheel animal, and the anguillæ of tiles. Nor is even this all: you may, if you choose, by the mere arrangement of the particles of matter, as I shall afterwards prove by experiment, at once produce myriads of animals, and bestow upon them motion, or in other words, the phenomena of sensibility. This, the experiments of Spallanzani, contrary to his own inclination, decidedly prove. If it be objected, that it may be as fairly argued, that sensation is something combined with these forms of matter, I answer, that we are not entitled to suppose any thing an independent being which never appears but in combination. Now, as we have shown that sensation is implicitly dependent upon, or connected with motion; and as this and all the other functions of the brain, are entirely the results and modifications of sensation, they also must be dependent on or connected with motion. Far be it from me to pretend to account for mental operation by mere physical motion. But, that motion accompanies all these processes, I am certain; nor can the supposition that motion is made use of in the most mysterious operations of the mind, possibly detract from the honour of a Deity, or from our admiration of natural operations. We have little need to be afraid of a moderate and rational materialism. It is the idealism of Berkeley, it is the scepticism of Hume—those dangerous opponents of such materialism, that have so deeply injured philosophy and religion. It is according to these systems, that prophets, apostles and miracles, are only ideas in the mind; and, indeed, the unreasonable dislike to a rational materialism, is alone chargeable with having led to the dangerous scepticism of Hume.