manner of learning the manual and liberal arts, &c. goes upon this doctrine as its foundation, and may be considered as the detail of it, in various circumstances. I here begin with the simplest case, and shall proceed to more and more complex ones continually, till I have exhausted what has occurred to me upon this subject.
This proposition, or first and simplest case of association, is manifest from innumerable common observations. Thus, the names, smells, tastes, and tangible qualities of natural bodies, suggest their visible appearances to the fancy, i.e. excite their visible ideas; and, vice versâ, their visible appearances impressed on the eye raise up those powers of reconnoitring their names, smells, tastes, and tangible qualities, which may not improperly be called their ideas, as above noted; and in some cases raise up ideas, which may be compared with visible ones, in respect of vividness. All which is plainly owing to the association of the several sensible qualities of bodies with their names, and with each other. It is remarkable, however, as being agreeable to the superior vividness of visible and audible ideas, before taken notice of, that the suggestion of the visible appearance from the name is the most ready of any other; and, next to this, that of the name from the visible appearance; in which last case, the reality of the audible idea, when not evident to the fancy, may be inferred from the ready pronunciation of the name. For it will be shewn hereafter, that the audible idea is most commonly a previous requisite to pronunciation. Other instances of the power of association may be taken from compound visible and audible impressions. Thus the sight of part of a large building suggests the idea of the rest instantaneously; and the sound of the words which begin a familiar sentence, brings the remaining part to our memories in order, the association of the parts being synchronous in the first case, and successive in the last.
It is to be observed, that, in successive associations, the power of raising the ideas is only exerted according to the order in which the association is made. Thus, if the impressions A, B, C, be always made in the order of the alphabet, B impressed alone will not raise a, but c only. Agreeably to which it is easy to repeat familiar sentences in the order in which they always occur, but impossible to do it readily in an inverted one. The reason of this is, that the compound idea, c, b, a, corresponds to the compound sensation C, B, A; and therefore requires the impression of C, B, A, in the same manner as a, b, c, does that of A, B, C. This will, however, be more evident, when we come to consider the associations of vibratory motions, in the next proposition.
It is also to be observed, that the power of association grows feebler, as the number either of synchronous or successive impressions is increased, and does not extend, with due force, to more than a small one, in the first and simplest cases. But, in
