_This the Basis of mental Reproduction._--It is to this general principle of suggestion or association that we are indebted for all mental reproduction. It is only as one idea or feeling is suggested by some other which has gone before, and with which it is in some way, and for some reason, associated in our minds, that any former thought or sensation is recalled, that any object which we have perceived or any scene through which we have passed, is mentally reproduced. It is thus that the sight of an object brings to mind occurrences connected with it in our history, that the same recalls the thing, that the words of a language bring to mind the ideas which they denote, or the characters on the musical staff, the tones which they represent. _Not a distinct Faculty._--It has been customary to speak of association of ideas as a distinct faculty of the mind. It is not properly so ranked. It is a law of the mind rather than a faculty of it--a rule or method of its action in certain cases; and the particular power of mind to which this rule applies is that form of simple conception which we term mental reproduction. _The Term Suggestion preferred by Brown._--In place of the term association, Dr. Brown would prefer the term suggestion as more correct. To speak of the association of ideas implies that they have previously coëxisted in the mind, and that the one now recalls the other in consequence of that previous coëxistence. That this is often the case is doubtless true, but it is also true that in many cases one idea suggests another with which it has not previously been associated in our minds. It is not necessary to the suggestion that there should be any prior association. An object seen _for the first time_ suggests many relative conceptions. The sight of a giant suggests the idea of a friend of diminutive stature, not because the two ideas have previously been associated, or the two objects have coëxisted, either in perception or conception, but because it is a law of the mind that one conception shall suggest another, either as similar, or as opposite, or in some other way related to it. This may be as truly a law of the mind, independent of association, as that light falling on the retina shall produce vision. It may seem mysterious that this should be so. Is it not equally mysterious that ideas which have formerly coëxisted should recall each other? The real mystery is the recurrence in any mode, and from any source, of the idea, without the recurrence of the external producing cause. For these reasons, Dr. Brown prefers the term _suggestion_ to _association_.