In my Lecture yesterday, after some further elucidation of the _triple division_ which we formed of the mental phenomena, as external or sensitive affections of the mind, intellectual states of the mind,--emotions,--I proceeded to consider the first of these divisions, of which the characteristic distinction is, that the phenomena included in it have their causes or immediate antecedents _external_ to the mind itself. In this division, I comprehended, together with the feelings which are universally ascribed to certain organs of sense, many feelings, which, though unquestionably originating in states of our bodily organs, as much as our other sensations, are yet commonly ranked as a different order--such as our various appetites, or rather that elementary uneasiness which is only a part, but still an essential part of our appetites, and which is easily distinguishable from the mere desire, which is the other element; since, however rapid the succession of them may be, we are yet conscious of them as successive. The particular uneasiness, it is evident, must have been felt as a sensation before the desire of that which is to relieve the uneasiness could have arisen. To the same class, too, I referred the various organic feelings, which constitute the animal pleasure of good health, when every corporeal function is exercised in just degree; and in a particular manner, our _muscular_ feelings, whether of mere general lassitude or alacrity; or those fainter differences of feelings which arise in our various motions and attitudes, from the different muscles that are exercised, or from the greater or less contraction of the same muscles. These muscular feelings, though they may be almost unnoticed by us, during the influence of stronger sensations, are yet sufficiently powerful, when we attend to them, to render us, independently of sight and touch, in a great measure sensible of the position of our body in general, and of its various parts; and comparatively indistinct as they are, they become,--in many cases, as in the acquired perceptions of vision, for example, and equally too, as I conceive, in various other instances, in which little attention has been paid to them by philosophers,--_elements_ of some of the nicest and most accurate judgments which we form. It is, however, to that widest and most important order of our external affections, which comprehends the feelings more commonly termed _sensations_, and universally ascribed to particular organs of sense, that we have now to proceed. In these, we find the rude elements of all our knowledge, the materials on which the mind is ever operating, and without which, it seems to us almost impossible to conceive that it could ever have operated at all, or could, even in its absolute inactivity, have been conscious of its own inert existence.