When a popular Anatomical Lecturer ventured, some years ago, to tell his pupils, that the zoological study of man' affords 'the only light capable of directing us through the dark regions of metaphysics, the only clew to direct our course through the intricate mazes of morals,' *—that comparative anatomy is, in short, the true key to legislation and ethics,-the pernicious tendency of his doctrine was sheathed, to a great extent, by its extravagant and manifest absurdity and presumption. But surely, not less presumption is chargeable on the lecturer on the physiology of mind, who so far forgets the proper boundary and the only legitimate object of his inquiry, as to intrude into the province of morals or theological philosophy, and to undertake to expound the nature of virtue and vice by an analysis of the phenomena of association or volition. The error of those papal censors who, in what are called the dark ages, made theology the arbiter of physical science, and deemed the discoverer of nature's laws guilty of heresy, was not really more irrational.

The remainder of this section of the Essay, is occupied with an extremely curious and interesting analysis of the elements of volition in different orders of sentient beings; beginning with the inferior animals, and tracing the rising gradation, in the principle of agency and the range of faculty and sensibility, up to man. This is a new application of that comparative process which has thrown no small light upon other branches of physiology. With what success the present Writer has brought it to bear upon his subject, our readers must be left to ascertain for themselves, as the train of observation will not admit of detached extract or analysis.

In the fifth section, (a continuation of the subject of the preceding one,) the Writer, having shewn wherein the principle of agency in man differs from that of the inferior families of the sentient system, exhibits the physiological history of the human mind, during the whole process of its growth and expansion, from the primary element of agency in the unintelligent, yet ever-active infant, to the full development of the moral being. This is executed with a felicitous combination of the philosophical and the graphical, which serves to relieve the

preposterous theory of morals' as a striking illustration of the fact, that intellectual philosophy is yet in its infancy.' His estimate of Brown, as an ethical writer, will be thought severe. Yet, with an obvious desire to do justice to the genius of this accomplished and amiable philosopher, Sir James Mackintosh is constrained to admit the obscurity, inconsistency, and dubious tendency of his speculations on moral sentiments.

* Lawrence. See Ecl. Rev. 2d Series. Vol. xvii. p. 483.

mon ground; and that the difference between the two parties should for ever be merged in a Biblical doctrine.' pp. 1—lii.

But a consummation like this, so devoutly to be desired, will be the result, our Author adds, not of the perfection of metaphysical theology, but of a better understanding of the special nature of the Document of Faith,' as, ' in the fullest sense, a 'Divine work.' Metaphysical reasoning, how rigid and exact soever, is not to be looked to as the means of adjusting Biblical controversies. It is one thing, to silence and confound an antagonist by force of logical strength;' it is quite another thing, to produce a permanent conciliation of differences.

In the following section, the Writer proceeds to inquire, in what manner, and to what extent, the question of liberty and necessity belongs to the Physiology of the Human Mind. If that branch of physiology is indeed to rank among the Physical Sciences,-if the study of mental phenomena is to be conducted upon the same principles of sound and careful induction from observation and experiment, that are now applied to every other branch of scientific investigation,-then, it is obvious, that the question of causation, or of free-will, can have no more to do with Intellectual Philosophy, than it has with comparative anatomy or botany, or than Berkeley's idealism has to do with chemistry. Whether the amiable Bishop's theory respecting the material world be true or false, it remains true, that sulphuric acid will change a vegetable blue to red, and that combustion goes on more rapidly in oxygen gas, than in common air. In like manner, it is, to the naturalist, a matter of absolute indifference, while informing himself of the internal 'structure of animals, or of their dispositions, faculties, and habits, in what way the systems of idealists, of materialists, of 'necessitarians, or of sceptics are disposed of,' So, in conducting a scientific inquiry respecting the mental processes of perception, the laws of volition, or the nature and operation of moral emotions,-all pure matters of physiological fact,-it ought to be felt, that the results of such investigation are as absolutely independent of metaphysical dogmas and abstract truths, as are the affinities of acids and the crystallization of salts. There would indeed,' continues the Writer, never 'have been occasion even so much as to affirm this inde'pendence of physics and metaphysics, were it not that the ' immemorial practice of confounding the science of the human mind with pure abstractions, has filled both departments of 'intellectual philosophy with absurdity, and has detained both, 'to the present day, in a state of infancy.'

* In a note to a former page, the Writer adverts to Dr. Brown's

When a popular Anatomical Lecturer ventured, some years ago, to tell his pupils, that the 'zoological study of man' affords the only light capable of directing us through the dark regions ' of metaphysics, the only clew to direct our course through the intricate mazes of morals,' *—that comparative anatomy is, in short, the true key to legislation and ethics,-the pernicious tendency of his doctrine was sheathed, to a great extent, by its extravagant and manifest absurdity and presumption. But surely, not less presumption is chargeable on the lecturer on the physiology of mind, who so far forgets the proper boundary and the only legitimate object of his inquiry, as to intrude into the province of morals or theological philosophy, and to undertake to expound the nature of virtue and vice by an analysis of the phenomena of association or volition. The error of those papal censors who, in what are called the dark ages, made theology the arbiter of physical science, and deemed the discoverer of nature's laws guilty of heresy, was not really more irrational.

The remainder of this section of the Essay, is occupied with an extremely curious and interesting analysis of the elements of volition in different orders of sentient beings; beginning with the inferior animals, and tracing the rising gradation, in the principle of agency and the range of faculty and sensibility, up to man. This is a new application of that comparative process which has thrown no small light upon other branches of physiology. With what success the present Writer has brought it to bear upon his subject, our readers must be left to ascertain for themselves, as the train of observation will not admit of detached extract or analysis.

In the fifth section, (a continuation of the subject of the preceding one,) the Writer, having shewn wherein the principle of agency in man differs from that of the inferior families of the sentient system, exhibits the physiological history of the human mind, during the whole process of its growth and expansion, from the primary element of agency in the unintelligent, yet ever-active infant, to the full development of the moral being. This is executed with a felicitous combination of the philosophical and the graphical, which serves to relieve the

preposterous theory of morals' as a striking illustration of the fact, that intellectual philosophy is yet in its infancy.' His estimate of Brown, as an ethical writer, will be thought severe. Yet, with an obvious desire to do justice to the genius of this accomplished and amiable philosopher, Sir James Mackintosh is constrained to admit the obscurity, inconsistency, and dubious tendency of his speculations on moral sentiments.

* Lawrence. See Ecl. Rev. 2d Series. Vol. xvii. p. 483.

dryness of the abstract argument. The conclusion to which we are conducted is, that, in ascending from mechanical and chemical to animal agencies, we are not passing from infallible to fallible sequencies, nor from causation to contingency, nor from necessity to its opposite, but simply, from a less complex 'system of causation to one that is more so.'

The one system is as truly causal as the other; or else, neither is it at all so both are necessary, or neither is necessary; both are contingent, or neither. If the one system may be foreknown, so may the other; or neither. If there be any fortuity in the universe, the universe is a mass of fortuities.'

Nevertheless, the distinction of more or less complex, is, to the mind, a most important one; since a complexity of causes, by setting human calculation at defiance, assumes the appearance of uncertainty and fortuity. The course of a bullet shot out of a musket, may be calculated with precision, being determined by a few known powers and laws. And so is the course of a bullet that is violently shaken in a canister. But who', asks our Writer, would attempt to forecast the thousand suc'cessive reverberations of the ball from the sides of the canister, even though it were agitated in the most exact and regular manner; much less if it were shaken by the hand?

Yet is that track, though not to be calculated by human faculties, as strictly the consequence of the combined laws of impulse and gravitation, as is the course of a bullet shot from a gun; and if the one may be calculated by human intelligence, the other might also be foreknown by super-human faculties. Every one is aware that the application of the word chance to the course of the ball in the canister, is a mere colloquial impropriety.' p. xvi.

When we turn to the animal world, the complexity of causes becomes so vastly increased, by the introduction of new powers into the machinery, that all human calculation is set at defiance. We can, with regard to their movements,' merely forecast pro'babilities'. Yet are they not the less causal, or more fortuitous, because by us incalculable, and therefore to us uncertain. Every new power admitted into a complex machinery, obviously tends to multiply the variations of its movements. This general principle is, however, open to one important exception. If the new and superadded power be of a paramount or commanding sort, it will simplify the movements, rather than complicate them, and thereby bring them more within the reach of calculation. For instance, the mental machinery of the adult is more complex than that of the infant, inasmuch as new faculties and susceptibilities have come into play; but the agency of the man is often so governed by a vehement animal desire, or a ruling mental passion, long indulged, that

his movements will be far less variable and uncertain than those of the infant.

A similar uniformity and simplification may result from the predominance of virtuous emotions. Or, again,-and this is an instance of the most significance, that very expansion of the intellectual faculties which imparts the greatest organic complexity to the machine, does at the same time, when it reaches its perfection, restore (if we may so speak) to the operations of the mind the most absolute simplicity. Truth is one; and it is the glory and perfection of the intellectual nature to perceive that oneness; and in proportion as truth is so perceived, and embraced, and delighted in, the agency of the being will become more simple, and calculable, and will lose its character of variableness. The same is true of the perfection of moral faculties; and it may, as a general principle, be affirmed, that perfection, in all orders, and of all kinds, tends, with equal steps, towards simplicity, uniformity, and constancy.' pp. xcvii, xcviii.

6

But what is gained by applying to this simplicity or constancy which is the character of perfection, the term necessity? Obviously nothing but a confusion and perversion of ideas. Apart from the poetry of metaphysics,' observes our Author, nothing is more simple than the certain connexion between perfect intelligence and the perception of a truth presented to it. Who would wish to be endowed with a freedom from this sort of necessity?'* That is, to be reduced to the intellectual contingency, if we may so speak, of infancy, of ignorance, or of insanity? Equally certain is the connexion between perfect goodness and the choice of what is virtuous and right. Who but a profligate would wish to be excused from this species of what is called moral necessity, or would court a mode of agency as far removed as possible from the certainty arising from an over-ruling moral principle? To be bound by this necessity', it is finely remarked, 'is the true liberty †; and in fact, as we ' approach to the high ground of intellectual and moral perfec'tion, liberty and necessity merge in one and the same condi'tion; and he is the most nobly free, whose reason and whose volitions are the most invariable and uniform; or, to use an 'improper term, are the most imperatively necessary."

Nothing', continues our Author, ought to be wished for by any order of beings, but that its mechanism should be so constructed as to secure (in the ordinary course of things) its welfare. It is by such a well-ordered construction of parts and functions, that the preservation, and reproduction of the animal tribes are actually secured: their ma

The indifference of equilibrium, Leibnitz remarks, is simply a 'power to act without reason'; a strange privilege, were it conceivable. +Se plaire à pécher est la liberté d'un esclave.' Augustin ap. Leibnitz.