On the whole, we think it clear that neither by Phrenology, which adds merely to the number of our material "organs," nor by Mesmerism, which adds _one_ to the number of the "influences" by which we are affected, nor by Clairvoyance, which adds the phenomena of _magnetic_ to those of _natural_ sleep, is the state of the question materially altered from what it was before these additions were made to Physiological speculation. And hence those who are well versed in our older writers on the doctrine of "spirit" and "matter," will be sufficiently furnished with weapons for repelling the more recent assaults of Materialism. If any one has read and digested the Treatises of Dr. Samuel Clarke, in his replies to Dodwell, Collins, and Leibnitz; the "Free Discussion" between Dr. Priestley and Dr. Price; the "Examen du Materialisme" by Bergier, in reply to the "Systeme de la Nature;" and the writings of Andrew Baxter, Drew, Ditton, and others, on the same subject, he will find little difficulty in grappling with the arguments of Comte, Atkinson, and Martineau. He will see at once that the main, the fundamental question, is not materially affected by the advances which have been made in Physiological discovery. These discoveries may have extended our knowledge respecting _the relations_ which subsist between the "mind" and the "body;" they have in no degree served to obliterate the _distinction betwixt the two_. In perfect consistency, however, with this conviction, we may frankly avow our opinion, that some of the older opponents of Materialism adopted a method of stating their argument which appears to us to be liable to just exception, and which the progress of Physical, and especially of Chemical science, has tended greatly to discredit. They seem to have been apprehensive that by ascribing any peculiar properties or active powers to matter, they might incur the hazard of weakening the grounds on which they contended for the spirituality of man and the supremacy of God. Thus, in the "Inquiry into the Nature of the Human Soul," by Andrew Baxter, the existence of any active property or power in matter is explicitly denied, and the only property which is ascribed to it is a certain passive power, or "vis inertiae," by which it is incapable of changing its state, whether of rest or of motion. This "vis inertiae" is not only supposed to be the sole property of matter, but is even held to be inconsistent with, and exclusive of, any active power whatever; and all the effects which are usually said to be produced by it are ascribed to the power of an immaterial Being. We are told that "vis inertiae," or "a resistance to any change of its present state, is essential to matter, and inconsistent with any active power in it;" that "all gravity, attraction, elasticity, repulsion, or whatever other tendencies to motion are observed in matter (commonly called natural powers of matter), are not powers implanted in matter or possible to be