powers of living bodies. The first of these depends upon the circumstance, that, in investigating the relations and tendencies in these cases, we are generally obliged to trust to observation alone, as the phenomena happen to be presented to us, and cannot confirm or correct these observations by direct experiment. And as the actual connexions in which the phenomena occur to us are often very different from their true relations, it is in many cases extremely difficult to ascertain the true relations; that is, to refer effects to their true causes, and to trace causes to their true effects. Hence just conclusions are arrived at slowly, and after a long course of occasional observations; and we may be obliged to go on for a long time without acquiring any conclusions which we feel to be worthy of confidence. In these sciences, therefore, there is great temptation to grasp at premature inductions; and when such have been brought forward with confidence, there is often difficulty in exposing their fallacy; for in such a case it may happen, that as long a course of observation is required for exposing the false conclusion, as for ascertaining the true. In physical science, on the other hand, a single experiment may often overturn the most plausible hypothesis, or may establish one which was proposed in conjecture.

The second source of uncertainty in this class of sciences consists in the fact, that, even after we have ascertained the true relations of things, we may be disappointed of the results which we wish to produce, when we bring their tendencies into operation. This arises from the interposition of other causes, by which the true tendencies are modified or counteracted, and the operation of which we are not able either to calculate upon or to control. The new causes, which operate in this manner, are chiefly certain powers in living animal bodies, and the wills, feelings, and propensities of masses of human beings, which we have not the means of reducing to

any fixed or uniform laws. As examples of the uncertain sciences, therefore, we may mention medicine and political economy; and their uncertainty is referable to the same sources, namely, the difficulty of ascertaining the true relations of things, or of tracing effects to their true causes, and causes to their true effects; and the intervention of new causes which elude our observation, while they interfere with the natural tendencies of things, and defeat our attempts to produce certain results by bringing these into action. The scientific physician well knows the difficulty of ascertaining the true relations of those things which are the proper objects of his attention, and the uncertainty which attends all his efforts to produce particular results. A person, for example, affected with a disease, recovers under the use of a particular remedy. A second is affected with the same disease, and uses this remedy without any benefit; while a third recovers under a very different remedy, or without any treatment at all. And even in those cases in which he has distinctly ascertained true relations, new causes intervene and disappoint his endeavours to produce results by means of these relations. He knows, for example, a disease which would certainly be relieved by the full operation of diuretics;—and he knows various substances which have unquestionably diuretic virtues. But in a particular instance he may fail entirely in relieving the disease by the most assiduous use of these remedies;-for the real and true tendencies of these bodies are interrupted by certain other causes in the constitution itself, which entirely elude his observation, and are in no degree under his control.

It is unnecessary to point out the similarity of these facts to the uncertainty experienced by the statesman in his attempts to influence the interests, the propensities, and the actions of masses of mankind; or to show how often measures which have

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