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THE DOCTRINES OF VIBRATIONS AND ASSOCIATION IN GENERAL.

CHAP. I.

THE GENERAL LAWS ACCORDING TO WHICH THE SENSATIONS AND MOTIONS ARE PERFORMED, AND OUR IDEAS GENERATED.

M Y chief design in the following chapter is briefly to explain, establish, and apply the doctrines of vibrations and association. The first of these doctrines is taken from the hints concerning the performance of sensation and motion, which Sir Isaac Newton has given at the end of his Principia, and in the Questions annexed to his Optics; the last, from what Mr. Locke, and other ingenious persons since his time, have delivered concerning the influence of association over our opinions and affections, and its use in explaining those things in an accurate and precise way, which are commonly referred to the power of habit and custom, in a general and indeterminate one.

The doctrine of vibrations may appear at first sight to have no connexion with that of association; however, if these doctrines be found in fact to contain the laws of the bodily and mental powers respectively, they must be related to each other, since the body and mind are. One may expect, that vibrations should infer association as their effect, and association point to vibrations as its cause. I will endeavour, in the present chapter, to trace out this mutual relation.

The proper method of philosophizing seems to be, to discover and establish the general laws of action, affecting the subject under consideration, from certain select, well-defined, and well-attested phænomena, and then to explain and predict the other