How much more highly is he deserving of esteem and immortality, than the conqueror who erects a vain renown upon the desolation of countries and the destruction of his fellowmen, and the monuments of whose glory are steeped in tears of the widow and the orphan, and besmeared with the blood of human victims!

BOOK I.-CHAPTER I.

Of the two great departments of Science.

PHILOSOPHY, taken in the widest extent of the term, is naturally divided into two great departments. The first, embraces all the inquiries of the human understanding in reference to matter, its properties and operations, and is denominated physical science; the second is a like investigation relative to mind, and has received the appellation of moral philosophy, or, perhaps, the still more appropriate title of the science of the human mind. Matter and mind, therefore, present the two great dominions which nature opens to our view, and which it is the province of philosophy to explore and cultivate. These are the only substances, with which the powers furnished us by the Creator, enable us to converse. Whether there may not be an intermediate substance, or intermediate substances, between matter and mind, partaking of the properties of neither the one nor the other, it is impossible for us to determine, and would be useless to inquire. That there are various grades of intelligent beings throughout the universe, some of whom as greatly surpass the human race, in the powers with which they are endowed, as the human race does the lowest species of animals possessed of sagacity, would, independently of revelation, seem in a high degree presumable from the analogy of nature. When we reflect upon the numberless links in the chain of animated nature, commencing from man, and terminating in the most insignificant creature possessed of life, sense, and spontaneous motion, it seems extremely improbable, that there are no grades of intelligent beings to fill up the immense chasm between the limited and finite mind of man, and the infinite mind of the creator. We should in vain, however, exhaust the strength of our understandings in dis

quisitions of this nature. Although it might be gratifying to a laudable curiosity, to attain to knowledge and certainty in such matters, yet, it is not to be denied that they are without the legitimate province of philosophy, and guarded by impassible barriers against the approach and examination of the human faculties. Body and spirit, the material and immaterial principle, are the two substances with which we are perpetually conversant, and to enlarge and extend our acquaintance with which, is the great object of philosophical investigation and research. But it is to be remarked, that our acquaintance, even with these objects that have become so very familiar to us, is not without its limits. It is evident we are furnished with no powers, that enable us to discern the inward structure and constitution of matter or mind, and that all our information concerning them, must be confined to the knowledge we can obtain of their properties and operations. "What the real substance of any thing is, says Newton,* we know not. In bodies we see only their figures and colours, we hear only the sounds, we touch only their outward surfaces, we smell only the smells and taste the savours, but their inward substances are not to be known either by our senses or by any reflex act of our minds." As, then, it is an admitted maxim in philosophy, that we are endowed with no faculties that enable us to penetrate into the hidden essences of things, and from a knowledge of those essences to determine a priori, the results of their future actions upon each other, all our acquaintance with the qualities and operations both of body and mind must depend solely upon experience. Considering this circumstance, it seems astonishing that the method of inquiry proposed by lord Bacon and denominated his plan of induction, when we reflect that its necessity and use are so obvious and important to mankind, not only as a vehicle for the advancement of science, but as

* General scholium, book 3.

an indispensable instrument for the daily and ordinary acquisition of knowledge, should have been so long unknown to the philosophic world. This method of induction teaches the inquirer into nature, instead of indulging the pride of wisdom, and dogmatically pronouncing his decrees and perverting her judgments to suit his own hypothesis, to become the humble pupil of nature, be instructed in her school, and contented with performing the part of a modest and faithful interpreter of her signs; it subjects the investigator of truth to so severe a mental discipline, that he is required to discard all theories not substantiated by ample observation and experience, and not attempt to establish general principles of science, until he has ascended to them through a just gradation, and from a complete and ample collection of facts. It is at once the vehicle by which we attain to those simple lessons of practical wisdom, which are necessary to our safety and well being, and the most sublime discoveries of science. As it naturally falls in with our plan, however, to treat of this method of inquiry during the progress of these dissertations, we dismiss the subject for the present, and proceed, without further delay, to explain the nature, object and uses of the science of the human mind.

The object of pneumatology, or the science of the human mind, is to trace the progress of the understanding in the acquisition of knowledge, to pursue it from its earliest beginnings in those simple perceptions to which it attains by means of the external senses and reflex acts of its own, to its most complex and sublime combinations and conclusions. It ascertains the constituent principles of the mind, solves all the phenomena exhibited by it, penetrates to the deep foundations of truth and certainty, weighs, in the scales of right reason, the different degrees of evidence upon which our assent is grounded, shows in what cases absolute demonstration may be attained, and when we should rest contented with moral certainty, or even strong probability, and, finally,

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detects the errors to which we are liable, unfolds the latent sources of them, and points out the true roads that lead, in the various departments of science, to that kind of evidence and certainty, to which, from the limited nature of our faculties, we should yield an entire assent. Certainly no science could be more important, not only as it constitutes in itself a most interesting branch, but as in it are laid the foundations of every other; by its principles their certainty, permanence and usefulness are tested, and the best methods disclosed by which they may be advanced on the way towards improvement and perfection.