In proceeding to examine and compare the mental phenomena, the first circumstance that strikes us, prior to any attempt to arrange them in classes, is, that the mind which exhibits these is susceptible of a _variety of feelings_, every new feeling being a change of its state; and, indeed, it is by such changes alone that it manifests itself, either in our own consciousness, or in the actions of our fellow men. If it could exist only in _one everlasting_ state,--such as now constitutes the feeling of any particular moment,--it is quite superfluous to say, that it could not _reason_ upon this state,--for this very reasoning would itself imply the change, which is supposed to be impossible; and as little could this one unchanged and unchangeable feeling be an object of reasoning to others, even if there were any mode of its becoming manifest to them, which there evidently could not be. It is, perhaps, even not too extravagant an assertion of Hobbes, who supposes a mind so constituted as to perceive only one colour, and to perceive this constantly, and affirms, that, in that case, it would be absurd to say that it had any perception at all, being rather, as he expresses it, stupified than seeing. “Attonitum esse et fortasse aspectare eum, sed stupentem dicerem, videre non dicerem; adeo sentire semper idem, et non sentire ad idem recidunt.” Mind, then, is capable of existing in _various states_; an enumeration of the leading classes of which, as I before remarked, is all that constitutes our definition of it. It is that, we say, which perceives, remembers, compares, grieves, rejoices, loves, hates; and though the terms, whatever they may be, that are used by us, in any such enumeration, may be few, we must not forget that the terms are mere inventions of our own for the purpose of classification, and, that each of them comprehends a variety of feelings, that are as truly different from each other, as the classes themselves are different. _Perception_ is but a single word; yet, when we consider the number of objects that may act upon our organs of sense, and the number of ways in which their action, may be combined, so as to produce one compound effect, different from that which the same objects would produce separately, or in other forms of combination, how many are the feelings which this single word denotes!--so many, indeed, that no arithmetical computation is sufficient to measure their infinity.