To account for the harmonious concurrence of motions and processes that distinguish living animals, a MATTER OF LIFE has been supposed, and its nature conjectured to be some modification[2] of electricity or galvanism, and which being unsupported, is not deserving of further comment. Another sect of physiologists has conceived that life is the immediate result of a particular organization; but they are unable to demonstrate that any arrangement of parts is consequently endowed with vital actions. This arrangement of particular tissues, may be absolutely necessary for the performance of various functions in the living state: but this is altogether different from the energy or cause that excites the action. A violin and its bow are prepared to "discourse most excellent music," yet they are mute until guided by the skilful hands of the performer. When death ensues from many diseases, the organization remains, for without this concession our anatomical knowledge must be very imperfect. Thus the nature of life, whether it be developed in the vegetable creation, or display its admirable complications in the higher animals, is inexplicable on any of the principles that regulate our philosophy, and can only be referred to the contrivance and disposition of infinite wisdom: yet the vehicle in which these stupendous operations are conducted owns a material basis: even the confused mass that composes the earth we tread on possesses certain intrinsic properties. Every atom is subjected to definite regulation, and without exaggeration, may be considered endowed with instinctive tendency to coalesce or disunite under favourable opportunities, and the correct observation of these habitudes, constitutes the foundations of chemical science. When the power and intelligence of the supreme Artificer is conspicuous in the ultimate particles of matter, we ought to be more temperate in our invectives against the doctrine of materialism.
Ideas have been generally employed, and held competent, by many of the tribe of metaphysicians, to explain the phenomena and operations of our intellectual nature: but they have failed in the attempt. They have endeavoured to confer on them an agency they do not possess, and have given the mind a dominion over them that it cannot exert.[3] Ideas are the memorial phantasms of visual perception, a largess bestowed, perhaps exclusively, on the sense of sight, and this bounty contributes essentially to the acquirement and retention of knowledge. They are the unfading transcripts of vision, and they exhibit the original picture to the retrospect of memory. They are but little under the immediate direction of the will, and cannot be arbitrarily summoned or dismissed, but owe their introduction to a different source, to be explained hereafter. They perform important offices, although they are not the materials to rear and consolidate the edifice of thought.