been planned with every effort of human wisdom fail of the results which they were intended to produce, or are followed by consequences remarkably different. Nothing indeed can show in a more striking manner the uncertainty which attaches to this science, than the different aspects in which the same measure is often viewed by different men distinguished for political wisdom and talent. I abstain from alluding to particular examples, but those accustomed to attend to public affairs will find little difficulty in fixing upon remarkable instances in which measures have been recommended by wise and able men, as calculated to lead to important benefits, while others of no inferior name for talent and wisdom have, with equal confidence, predicted from them consequences altogether different. Such are the difficulties of tracing effects to their true causes, and causes to their true effects, when we have to deal, not with material substances simply, but with the powers of living bodies, or with the wills, the interests, and propensities of human beings.

One other reflection arises out of the view which has been given of this important subject. The object of all science, whether it refer to matter or to mind, is simply to ascertain facts, and to trace their relations to each other. The powers which regulate these relations are entirely hidden from us in our present imperfect state of being; and by grasping at principles which are beyond our reach, we leave that path of inquiry which alone is adapted to our limited faculties, and involve ourselves in error, perplexity, and darkness. It is humbling to the pride of human reason, but it is not the less true, that the highest acquirement ever made by the most exalted genius of man has been only to trace a part, and a very small part, of that order which the Deity has established in his works. When we endeavour to pry into the causes of this order, we perceive the operation

of powers which lie far beyond the reach of our limited faculties. They who have made the highest advances in true science will be the first to confess how limited these faculties are, and how small a part we can comprehend of the ways of the Almighty Creator. They will be the first to acknowledge, that the highest acquirement of human wisdom is to advance to that line which is its legitimate boundary, and there contemplating the wondrous field which lies beyond it, to bend in humble adoration before a wisdom which it cannot fathom, and a power which it cannot comprehend.

INQUIRIES

CONCERNING THE

INTELLECTUAL POWERS, &c.

PART I.

OF THE NATURE AND EXTENT OF OUR
KNOWLEDGE OF MIND.

THE mind is that part of our being which thinks and wills, remembers and reasons: we know nothing of it except from these functions. By means of the corporeal senses it holds intercourse with the things of the external world, and receives impressions from them. But of this connexion also we know nothing but the facts; when we attempt to speculate upon its nature and cause, we wander at once from the path of philosophical inquiry into conjectures which are as far beyond the proper sphere as they are beyond the reach of the human faculties. The object of true science on such a subject, therefore, is simply to investigate the facts, or the relations of phenomena, respecting the operations of mind itself, and the intercourse which it carries on with the things of the external world.

This important rule in the philosophy of mind has been fully recognised in very modern times only, so

that the science, as a faithful interpretation of nature, may be considered as of recent origin. Before the period now referred to the investigation was encumbered by the most fruitless speculations respecting the essence of mind, and other discussions which led to no discovery of truth. It was contended, for example, that the mind cannot act where it is not present, and that consequently it cannot be said to perceive external objects themselves, but only their images, forms, or sensible species, which were said to be conveyed through the senses, and represented to the mind in the same manner in which images are formed in a camera obscura. By the internal functions of mind these sensible species were then supposed to be refined into phantasms, the objects of memory and imagination; and these, after undergoing a further process, became intelligible species, the objects of pure intellect. By a very natural application of this doctrine, it was maintained by Bishop Berkeley and the philosophers of his school, that as the mind can perceive nothing but its own impressions or images, we can derive no evidence from our senses of the existence of the external world; and Mr. Hume carried the argument a little further, by maintaining that we have as little proof of the existence of mind, and that nothing exists in the universe except impressions and ideas. Of another sect of philosophers who arose out of the same system, each individual professed to believe his own existence, but would not admit the existence of any other being; hence they received the appropriate name of Egoists.

The various eminent individuals by whom the fallacy of these speculations was exposed, combated them upon the principle that the doctrine of ideas is entirely a fiction of philosophers; and that a confidence in the information conveyed to us by our senses must be considered as a first truth, or a fundamental law of our nature, susceptible of no explanation, and admitting of no other evidence than that which is

derived from the universal conviction of mankind. Nor does it, to common minds, appear a slight indication of the validity of this mode of reasoning, that the philosophers who supported this theory do not appear to have acted upon their own system; but in every thing which concerned their personal accommodation or personal safety, showed the same confidence in the evidence of their senses as other

men.

The deductions made from the ideal theory by Berkeley and Hume seem to have been applications of it which its former advocates had not contemplated. But it is a singular fact, as stated by Dr. Reid, that nearly all philosophers, from Plato to Mr. Hume, agree in maintaining that the mind does not perceive external things themselves, but only their ideas, images, or species. This doctrine was founded upon the maxim that mind cannot act where it is not present; and we find one writer only who, admitting the maxim, called in question the application of it so far as to maintain that the mind, in perceiving external things, leaves the body, and comes into contact with the objects of its perception.

Such speculations ought to be entirely banished from the science of mind, as not only useless and unprofitable, but as referring to things entirely beyond the reach of the human faculties, and therefore contrary to the first principles of philosophical investigation. To the same class we are to refer all speculations in regard to the essence of mind, the manner in which thought is produced, and the means by which the intercourse is carried on between the mind and external objects. These remarkable functions were at one time explained by an imaginary essence called the animal spirits, which were supposed to be in constant motion, performing the office of messengers between the brain and the organs of sense. By another class of philosophers, of no very ancient date, thinking was ascribed to vibrations in