_General Character of this Power._--It has not been usual to treat of Attention as one of the distinct faculties of the mind. It is doubtless a power which the mind possesses, but like the power of conception, or more generally the power of thought and mental apprehension, it is involved in and underlies the exercise of all the specific mental faculties. Nor is it, like consciousness, confined to a distinct department of knowledge, viz., the knowledge of our own mental states. It is subsidiary to the other mental powers, rather than a faculty of original and independent knowledge. It originates nothing--teaches nothing--puts us in possession of no new truth--has no distinct field and province of its own. And yet without it other faculties would be of little avail. _Definitions._--If it were necessary to define a term so well understood, we might describe it as the power which the mind has of directing its thoughts, purposely and voluntarily, to some one object, to the exclusion of others. It is described by Dr. Wayland as a sort of voluntary consciousness, a condition of mind in which our consciousness is excited and directed by an act of the will. He speaks also of an involuntary attention, a state of mind in which our thoughts, without effort or purpose of our own, are engrossed by objects of an exciting nature. It may be questioned, perhaps, whether this is properly attention. Only in so far as attention is a voluntary act is it properly a power of the mind, and only in so far does it differ from the simple activity of thought, or of consciousness. The latter is always involuntary, and in this it differs from attention. _Instances in Illustration._--It can hardly be necessary to illustrate by example the nature of a faculty so constantly in exercise. Every one perceives, for instance, the difference between the careless perusal of an author--the eye passing listlessly over the pages, and the mind receiving little or no impression from its statements--and the reading of the same volume with fixed and careful attention, every word observed, every sentiment weighed, and the whole mental energy directed to the subject in hand. We pass, in the streets of a crowded and busy city, many persons whom we do not stop to observe, and of whose appearance we could afterward give no account whatever. Presently, some one in the crowd attracts our notice. We observe his appearance, we watch his movements, we notice his peculiarities of dress, gait, manners, etc., and are able afterward to describe them with some degree of minuteness. In the former case we perceive, but do not attend. In the latter, we attend, in order to perceive.