this sort must be light and ineffectual without first ascertaining (if possible) the manner in which our ideas are produced, and the nature of consciousness, both of which I am utterly unable to comprehend. I have endeavoured simply to point out what it is that is to be accounted for, (the general feeling with which a reflecting man should set out in search of the truth) and the impossibility of ever arriving at it, if at the outset we completely cover over our own feelings with maps of the brain, dry skulls, musical chords, pendulums, and compasses, or think of looking into the bottom of our own minds by means of any other instrument than a sharpened intellect.
What I at first proposed was to shew, that association, however we may suppose it to be carried on, is not the only source of connection between our ideas, or mode of operation of the human mind. This has been assumed indirectly and I think proved with respect to similarity, &c. Here however a shrewd turn has been given to the argument by the Hartleians, who, admitting similarity among the causes of connection between our ideas, deny that it is any objection to their doctrine, for that this very example is easily resolved into a case of mere association. Similarity, they say, is nothing but partial sameness; and where part of a thing has been first associated with certain circumstances, and is afterwards conjoined with others, making in fact two different objects, it's recurrence in the second instance will necessarily recall the circumstances with which it was associated in the first[1]. In general we suppose that if we meet a person in the street with a face resembling some other face with which we are well acquainted, the reason why the one puts us in mind of the other is that the one is like
- ↑ See Priestley's Letters to a Philosophical Unbeliever.
