When we attentively measure the steps of our own minds in the act of thinking, and also observe the progress of others, it will be found that effective Thought does not result from this rapid and tumultuous rush of Ideas; but is a very deliberate, and in many cases painful elaboration: and must, when committed to writing, be subjected to subsequent revisals and repeated corrections, and which must be applied to the _words_ constituting the sentence in which the thought is contained. From this general view of the subject, it is concluded that Ideas, the residuary phantasms of visual perception, cannot directly constitute or become the immediate instruments of Thought. The present Essay being considered an humble attempt to investigate a portion of intellectual physiology, an apology will scarcely be deemed necessary for a short digression to inquire into the powers and faculties of the human mind: and which, when determined, may be viewed as the alphabet of mental science. Systems prematurely constructed, and under the impression of authority, have been especial impediments to our intellectual progress: and this truth has been remarkably exemplified in the works that have treated of the human mind. In the numerous treatises on this subject that have issued from the press, there is but little agreement concerning these powers or faculties, and it is evident that a definite number must be required: some writers enumerate more, others less, and it is not unusual for some of these metaphysical projectors to split a single and presumed faculty into a variety of subdivisions. To the acute and patient observer, it will appear that the operations of Nature are contrived with admirable simplicity; but man, in his endeavours to explain them, has generally resorted to a mysterious and discouraging complexity. Thus, as might be expected, the same faculty, according to different authorities, has dissimilar energies,--one is detected to encroach on the boundary of another, and when the mechanism of mind, fabricated by these scholastic dictators, is attempted to be set in motion, it is found incapable of working. For the grand moving power we have an undefined, and consequently unintelligible doctrine of _Ideas_, of supposed spiritual and directing agency; the admission of which would destroy the responsibility of a human being both here and hereafter, and degrade his ennobled condition to the instinct of the speechless brute. To endow these insubstantial and reflected phantasms with some activity and mimic play, a theory of the _association of Ideas_ has been erected, without having previously established that they are capable of such confederation. A wearisome catalogue of faculties, many of which are conjectural, has been enumerated; Abstraction, Conception, Contemplation, Consciousness, Comparison, Imagination, Judgment, Memory, Recollection, Reminiscence, Retention, Perception, Sensation, Reflection, Thought, Understanding, Volition, and many others