subject to motion by impulse from without, which seems to be answered in the negative; for it can scarcely be admitted that this Principle can be subject to external impulse, since its movements, if it do move, must result from sensual impressions.
Before proceeding further, let us consider the nature of motion; for it may not only be untrue that Vital Principle is, as some affirm, essentially self-motive or capable of producing motion; but it may be one of those entities to which motion cannot possibly belong; and it has already been said that the motor is not necessarily itself in motion.
Everything moved admits of being moved in two ways: either by itself or by something else; and by something else we mean whatever is moved from being in something which is moving, as sailors for instance,—for they are not moved as is the vessel, since it is moved by itself, but they are moved from being in that which is moved. This is clear by reference to their limbs—a particular movement of the feet is walking, and walking is man's progression; but the sailors do not at that time move by walking. Since then motion may be spoken of in this two-fold