To obtain knowledge we must exercise the perceptive faculties. The senses of seeing, hearing, smelling, tasting and touching are the only avenues by which knowledge can reach the mind. He whose observation has been the most comprehensive, and whose investigations have been the most thorough and accurate, is enabled to exercise the contemplative powers with the greatest pleasure and advantage. The distinct and graphic imagery of men, scenes, events, objects and their properties, with which he has stored his mind, will give correctness to his ideas, variety to his mental operations, comprehensiveness to his intellectual view, clearness to his judgment, and truth to his conclusions. Possessing the elements of correctness, he will also possess the elements of happiness and success. He is enabled to open the volume of Nature, and read, in her pages of rocks and stars, sublimer periods than the pen of superstition ever recorded. He stands perpetually in the vestibule of truth, opening on the fields of immensity, strewed with objects of reality, before the blaze of whose overpowering grandeur the throne and empire of fancy dwindle into insignificance. He is enabled to imbibe the fervor, inhale the inspiration, and enjoy the ecstatic delights which scientific truth alone can confer, and which in intensity and purity so far transcend the fanatic's wildest excitement. He is inducted into the secret by which science has achieved all her victories, and by which she has erected in such solid grace and grandeur those literary and philosophical structures which stand like imperishable columns amid the ruin of temples and kingdoms.

But the acquisition of these exalted attainments embraces the exercise of all the intellectual power on appropriate objects. The mental, like the corporeal powers, are various; they are differently organized and adapted to deal with objects of different natures; and, all require to be exercised judiciously, in order to be kept in a healthy tone. If any member of the body is disused, it will be deprived of its natural energy; if any faculty of the mind is disused, it will lose its natural strength. It is only when each faculty of mind and body is properly exercised that the health and vigor of the whole organism can be maintained. The physiological cause of the enervating effects of indolence, and the invigorating consequences of exercise, are found in those laws of the human organism, whereby the blood is increased in a member by exercise, and decreased by inertia, and a proportionable degree of strength imparted by one and, subtracted by the other. Now, the faculties employed in the process of meditation, comprehend but a small number of the mental powers; and if they are exclusively exercised, a superabundant volume of blood will be distributed to them, and they will absorb the aliment necessary for the subsistence of the others. The establishment of this inequality in the distribution of the blood will derange the harmonious condition of the cerebral organs; some will be overcharged, and either inflamed or constipated, and others impoverished or enervated. One class of the mental powers thus becoming over-excited, another class enfeebled, and a third paralyzed, the ideas which the mind, in this condition, is capable of elaborating, must necessarily be partial, defective, disjointed and grotesque; resembling those nightmares that flit in our sleep, or those monsters which are born without limbs, and marked with deformity and distortion. But when all the moral faculties are properly employed, they will all receive their appropriate nourishment and maintain their natural vigor. In consequence of a harmony, equality, unity and reciprocity of mental action, thus induced, all the powers will be preserved in healthy action—the perceptives in furnishing the mind with knowledge, memory in storing it up, order in classifying it, analogy in comparing it, judgment in deducing conclusions from it, taste in selecting what is most appropriate, fancy in adorning it; and all proceeding as naturally as the vital organ elaborates and vitalizes the blood, and the reproductive system transforms it into animal fluids and solids.

But the partial exercise of the mental faculties, embraced in the act of meditation, not only disproportionately develops the cerebral organs; but deranges those which it labors to keep in incessant activity. A period of rest after labor is indispensable to the maintenance of the health and vigor of the cerebral organs. Exercise increases the flow of blood to their parts; repose, by inducing the process of recuperation, not only restores their vigor but increases their healthy volume. The invigorating effect of sleep is derived from the profound slumber into which all the faculties are calmed, except those whose functions are destined to recuperate and vitalize the entire system. To labor to keep the meditative faculties in constant action is to interrupt the process of recuperation; and, consequently, to prevent them from becoming vitalized. The man who attempts to lift a weight beyond the capacity of his muscular vigor, may never afterward be enabled to raise the tenth part of what was within his former ability; and Sir Isaac Newton, whose powers of contemplation seemed almost superhuman, after he had enervated his facilities by impelling them to constant and excessive exercise, has furnished the world with an illustration of the imbecility it engendered, by his works on the prophecies.

But the principle of self-preservation inherent in the human mind, rebels against the destruction of its faculties. Habitually to exercise the contemplative faculties on one class of objects is a superhuman task. In spite of resistance the blood will pursue its natural course to the different organs of the brain, and by virtue of this fact, in conjunction with the natural condition of the system, instinct will prompt, thought intrude, emotion arise, appetite crave, passion yearn, distraction ensue; and under the external semblance of sanctity, a moral volcano will burn and heave. We may, by means of the theological subterfuge that the involuntary actions of the cerebral functions are the suggestion of impure and malignant fiends, apologize to our conscience for the intrusion of profane and worldly thoughts, but this device will not exorcise them. We shall find that in the effort to become automata, we are men; and that in the attempt to exercise one class of faculties and to concentrate: them perpetually on one class of objects, we have grappled with a giant, over whom, if we triumph it will be in our death-struggle.

It is impossible to think and feel by rule. Neither particular trains of thought, nor particular kinds of emotion are at the command of the will. Belief or unbelief, the sensations of contrition, of devotion, of hope, or any other sentiment or feeling can no moro be created by an act of volition, than can storms and earthquakes.. There is a secret power acting on the nervous system, over which the will has no control.

The state of the atmosphere, the sanity of the system, the unconscious power of imbibed principles, the recollections of the past, the circumstances of the present, and the prospects of the future, all like unseen spirits stir the soul's depths with ideas and passions, always involuntary, and sometimes as abruptly as an electrical flash. To attempt to subject the laws by which ideas and emotions are created to the power of the will, so that they may be conjured and shaped by its mandates, is to war, not only against the constitution of the human mind, but against the powers and elements of Nature.

SECOND. The Natural Effects of the Monastic Vow of Silent Contemplation.

Let us consider the character and products of the mind which the monastic vow of silent contemplation is calculated to create.

When liberal education has disciplined the intellectual powers, and study has enriched the mind with the facts and principles of science and literature, a philosopher may find in solitude an influence congenial to his high pursuits; and with his scientific instruments enlarging his field of vision, he may discover new secrets in the realms of Nature, and come forth from retirement a more useful member and a brighter ornament of society. But if with distinguished abilities, and the valuable results of an erudite industry, he should maintain perpetual silence, and continue for life in a secluded abode, he would be of no benefit to mankind, and neither win nor deserve the homage which they accord to scientific benefactors.

But the monks were very far from being philosophers. They were in general exceedingly illiterate. Some of their orders actually interdicted as profane any attempt to cultivate the intellectual powers, or to acquire either scientific or literary information. Filled with abject and obscene pilgrims, with slaves who knew of nothing but manual labor, with mechanics whose scanty wages had precluded the possibility of a rudimental education, with soldiers who had no knowledge but that of war, and who had fled before the victorious barbarian into obscurity for safety, it could not be expected that the monasteries with such material, imprisoned in solitude, deprived of social communion, enervated in mental capacity, and restricted in the exercise of their intellectual powers, could ever give birth to philosophers, or to anything but mental imbecility and moral monstrosities.