as primary sphere of action in the brain to account for B's not exciting a in the reverse order, &c. The question is how the impression of different objects at the same time, or in quick succession, gives the idea of one of those objects a power to excite the idea of the other, though the object is absent; and it is no answer to this question to say, that A being often repeated in connection with B, when it is afterwards excited, "leans towards B, and ends in it." Hartley says by way of breaking the difficulty, that the latter part of A is altered and modified by B. This is evident enough while B really acts upon the senses: but why should it be modified by it in the absence of B? This modification of the latter part of A by B is not the intermediate cause of the excitement of b, for b, the representative of B, must be excited, at least imperfectly, before it can modify A (B itself being nothing), and the point is how A, or a excites the movement connected with B and that only; not how, supposing this connection between them to be established, the one gradually passes into the other, and ends in it. I think Hartley constantly mistakes tracing the order of palpable effects, or overt acts of the mind, for explaining the causes of the fanciful connection between them, which he hardly ever does with a true metaphysical feeling. Even where he is greatest, he is always the physiologist rather than the metaphysician.
Perhaps a better way to discover the clue to the principle of association, setting aside all ideas of extension, contiguity, &c. would be by considering the manner in which the same conscious principle may be supposed to adapt itself to, to combine, and, as it were to reconcile together the actions of different objects impressed on it at once, and to all of which it is forced to attend at the same time; by which means
