_Office of this Power._--We have thus far treated of that power of the mind by which it takes cognizance of objects as directly presented to sense, and also of that by which it represents to itself former objects of cognition in their absence. But a large portion of our knowledge and of our mental activity does not fall under either of these divisions. There is a class of mental operations which differs from the former, in that they do not give us directly sensations or perceptions of things, do not present objects themselves; and from the latter, in that they do not represent to the thought absent objects of perception; which differ from both, in that they deal not with the things themselves, but with the properties and relations of things--not with the concrete, but with the abstract and general. This class of operations, to distinguish it from the preceding classes, we have named, in our analysis, the _reflective power_ of the mind. It comprises a large part of our mental activity. _Specific Character._--The form of mental activity which is characteristic of this faculty, is the perception of relations, that which Dr. Brown calls _relative suggestion_, but which we should prefer to term _relative conception_. The mind is so constituted that when distinct objects of thought are presented, it conceives at once the notion of certain relations existing between those objects. One is larger, one smaller, one is here, the other there, one is a part in relation to a whole, some are like, others unlike each other. The several relations that may exist and fall under the notice of this power of the mind are too many to be easily enumerated. The more important are, position, resemblance, proportion, degree, comprehension. All these may, perhaps, by a sufficiently minute analysis, be resolved into one--that of comprehension, or the relation of a whole to its parts. _Comprehensive of several Processes._--The faculty now under consideration will, on careful investigation, be found to underlie and comprehend several mental processes usually ranked as distinct operations and faculties of the mind, but which are at most only so many forms of the general power of relative conception. Such are the mental operations usually known as _judgment_, _abstraction_, _generalization_, and _reasoning_. Of these, and their relation to the general faculty comprehensive of all, we shall have occasion to speak further as we proceed.