Page:Essays on the Principles of Human Action (1835).djvu/100

distance of time they may have been severally impressed. If from the top of a long cold barren hill I hear the distant whistle of a thrush which seems to come up from some warm woody shelter beyond the edge of the hill, this sound coming faint over the rocks with a mingled feeling of strangeness and joy, the idea of the place about me, and the imaginary one beyond will all be blended together in such a manner in my mind as to become inseparable. Now the doctrine of vibrations appears absolutely to exclude the possibility of the union of all these into one associated idea, because as the whole of that principle is founded on the greater ease and certainty with which one local impression is supposed to pass into the seat of the next, and the greater force with which it acts there than it can do farther off, the idea of a visible object can never run into the notion of a sound, nor vice versâ, these impressions being of course conveyed along different nerves to different and very remote parts of the brain. Perhaps it will be said that all ideas impressed at the same moment of time may be supposed to be assigned to particular compartments of the brain as well as where the external objects are contiguous. To this I should answer that such a supposition does not at all account for what I have said above with respect to consciousness and the association of ideas from similarity, &c. and secondly, this supposition is neither included in Hartley's theory, nor does it seem to be compatible with it, as there is no other reason on the common material hypothesis for inferring the contiguity of our ideas in the brain than the contiguity of their external objects, and the impression of those objects on corresponding parts of the external sensible organ. The method taken by Hartley in detailing the associations, which take place between the ideas of each