_The true Doctrine._--All we can truly say, is, that the idea is awakened or called up in the mind when the occasion presents, is suggested _to_ it, not by it, suggested by the occasion, and not by the mind itself. The mind has the idea within, has, moreover, the faculty of _conceiving_ the idea, is so constituted, that, under certain circumstances, in view of what it observes without, or is conscious of within, the given idea is naturally and universally awakened in it; but the _source_ of the suggestion lies not within the mind itself, and is not to be confounded with the mind's faculty of conception.
_Use of the term by Reid and others._--Dr. Reid has been referred to as authority for the use of the word suggestion to denote the faculty in question. Dr. Reid makes use of the word, but not in the sense now intended, not to denote a specific faculty of the mind, coördinate with perception, memory, imagination, etc., not, in fact, as a faculty at all. He refers to the well known fact, that ideas are suggested to the mind by objects and events without, and by the sensations thus awakened; as, _e. g._, a certain sound suggests the passing of a coach in the street. So, also, one idea or sensation will suggest another. He uses the term to denote the suggestion of one thing _to_ the mind _by_ another thing, and not to denote a power in the mind of suggesting things to itself. This is the correct use, and was not original with Reid. Berkley had used the term in the same way before him. Locke had used the word _excited_ in the same sense. The idea expressed by these terms, and the use of the same or similar terms by which to express it, may be traced back as far, at least, as to the Christian Fathers. St. Augustine so uses it. Reid expressly applies the term to the perception of external objects, as, _e. g._, certain sensations suggest the notion of extension and space. This is correct use.
_The Facts in the Case._--The truth is, things exist thus and thus, and we are constituted with reference to them as thus existing. Sense and experience inform us of these existences and realities. Some of them are objects of direct perception by the senses, as matter and its qualities. Some of them are not directly objects of perception, but are suggested to the mind by the operations of sense, and are intuitively perceived by the mind, and recognized as truths and realities when thus suggested, as time, space, substance, cause, the right, the wrong, the beautiful, etc.