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On the Perceptions of Sense, the moral and social Nature
of Man, and the Powers of the human Mind and Intellect.
It was the doctrine of Aristotle, a doctrine long and obstinately disputed, but now very generally admitted, that all our direct knowledge originates in the perceptions of sense. The words, “nihil est in intellectu, quid non prius fuerit in sensu," have been universally attributed to him; but this does not appear to be proved. Of the five senses, that of touch, he observes, is generally diffused through the whole animal frame, and cannot therefore be destroyed without destroying the animal. The sense of taste, he regards as a particular kind of touch, requisite for the purpose of nutrition, and therefore essential to life; but the three other senses, always residing in particular organs, are in some animals altogether wanting, in others extremely imperfect; and even in those animals, in whom they are most vigorous, they are often, without destruction to the animal itself, overwhelmed, weakened, or totally destroyed, by the too powerful operations of their respective objects. The powers of imagination and memory, he says, owe their origin to the senses, and are common to man, with many other animals; but, if this be true, they must vary considerably in the different species. Aristotle investigated this difference, by analyzing the complex act of reminiscence, or recollection, in which the principles of association operate under the immediate direction of the human will. He enumerated them by saying, that they might be reduced to the four following heads: proximity in time; contiguity in place; resemblance, or similarity; contrariety or contrast; and he explained this by showing, that every exercise of recollection is a species of investigation.
It is the characteristic of animals, in contradistinction to the inanimate parts of nature, to be endowed with sensation; and whatever is endowed with sensation, must have perceptions of pain and pleasure ; and whatever has such perceptions, must feel the impulse of appetite, the great moving principle of all animated beings. But in the exercise of reminiscence, or the recovery of ideas, which is the immovable boundary between man and other animals, man alone recognises the divine principle of reason, or intellect, co-operating with the coarser powers of fancy or memory, since every act of reininiscence implies comparison; and every the slightest comparison, expressed in the simplest proposi. tion, indicates a substance different and separable from matter, a substance totally inconceivable by man in his present state, where the gross percep
tions of sense are the only foundations and sole materials of all others, how lofty soever and refined ; but it is a substance, notwithstanding, of whose existence we are assured, by our consciousness of its effects and energies. The existence of impercepti. ble, and therefore unknown, causes of our sensations, is maintained by Aristotle against the ancient sceptics, whose doctrines and errors he combated and confuted.
The perception of truth, says Aristotle, being altogether unrelated to time and space, must be totally dissimilar to any corporeal operation, and so essentially one simple energy, that it cannot, without absurdity, be supposed capable of division. But all the motions and actions of body, being performed in space and time, are therefore indefinitely divisible; and although their smallness, or quickness, soon escapes the perception of sense, and soon eludes the grasp of fancy; yet the intellect still pursues and detects them, knowing that they can never vanish into nothing, by this indefinite minuteness. By our divisions and subdivisions, without limit, we still leave, in the smallest particle of matter, body with its properties; and, after all the steps that can possibly be taken, we remain as distant from the point required, as at our first setting out. This point, therefore, it is impossible for man in this world, with his present powers or capacity, to attain; for, in the language of geometers, infinite will still be interposed between operations divisible and VOL. II.
indivisible, between perceptions of sense and perceptions of reason; between the nature and properties of mind and the nature and properties of matter.
It is, therefore, not sense nor fancy, but mind alone that recognises itself; and this intellectual substance, of which we must be contented, in our present state, merely to know the existence and to exercise the energies, is that which characterizes and ennobles the creature nian, and which gives him a resemblance to his Maker. It is this which, separated from the body, is then only properly what is termed immortal and divine; which does not decay with our corporeal powers, and whose energies are so totally different from those of orga. nized matter, that, whereas, our senses are easily fatigued, overpowered, and destroyed, by the force and intensity of objects sensible; the intellect is roused, quickened, and invigorated, by the force and impression of objects intelligible. Instead of being overstrained or blunted by them, it is sharpened and fortified, amidst obstinate exertions, and finds in such alone its best improvement and most exquisite delight. It is therefore evident, that the powers and perfections of mind, or intellect, must be very different from those of matter, or the senses; the latter producing only momentary enjoyments, the other, those of endless energies and gratifications, to endless time.
Having recognised the dignity and powers of man, Aristotle, throughout his works, examines how those powers have been exercised in rearing the fair fabric of science. When the mind of man shall be improved by the exercise of virtue and religion, it is natural that he will possess more sublime and perfect intelligence, and the divine truth may then be imparted to him, which, in his present state, he would not be able to comprehend. It is evident, says Aristotle, that the human mind is capable of intelligence before it is actnally intelligent; hence, it is capable of improvement; but all intelligence, in capacity, is derived from intelligence in energy; that is, from God. The mind, therefore, when separated from the body, assumes its true nature, activity, and dignity, and is then better and happier than it was before.
There must be some principle, or first cause of virtue, intellect, mind, and truth, or they could not exist; for whatever really exists, must have a cause of existence. Democrates said, that truth either did not exist, or that, by man at least, it was not to be discovered. Protagoras, the sophist, maintained, that man was the measure of all things which were true or false, good or bad, merely according to his conception of them. It is melancholy, says Aristotle, to hear those sceptics, who may be best expected to see and know what is true, maintain such opinions. There are, as he justly observes, existences, firm and immovable, though altogether imperceptible to our corporeal