IDEAS, (Encycl.) The origin of ideas has been a long time disputed among philosophers. The Peripatetics maintain, that external objects emit species which resemble them all around; and that these species, striking on our senses, are by them transmitted to the understanding; and that, being material and sensible, they are rendered intelligible by the active intellect; and are at length received by the passive. Others are of opinion, that our souls have of themselves the power of producing ideas of things we would think upon; and that they are excited to produce them by the impressions which objects make on the body, tho' these impressions are not images in any respect like the objects that occasioned them. And in this, say they, it is, that man is made after the image of God, and that he partakes of his power; for as God made all things out of nothing, and can reduce them to nothing when he pleases, so man can create as many ideas as he pleases, and annihilate them when he has done.
Others
Others maintain, that the mind has no occasion for any thing beside itself to perceive objects; and that, by considering itself, and its own perfections, it is able to discover all things that are without. Others, with Des Cartes, hold, that our ideas were created and born along with us.
Malebranche, and his followers, assert, that God has in himself the ideas of all the beings he has created; that thus he sees all things, in considering his own perfections, to which they correspond; and that, as he is intimately united to our souls, by his presence, our mind sees and perceives things in him which represent created beings; and that it is thus we come by all our ideas. He adds, that though we see all sensible and material things in God, yet that we have not our sensations in him. When we perceive any sensible object, in our perception is included both a sensation and a pure idea. The sensation is a modification of the soul, and it is God who causes it in us: but for the idea joined with the sensation, it is in God; and it is in him that we see it.
The Cartesians distinguish three kinds of ideas. The first, innate; such, they say, is that we have of God, as of a Being infinitely perfect. The second, adventitious; which the mind receives in proportion as bodily objects present themselves to our senses: such is the idea of body, sound, figure, light, &c. The third, according to these philosophers, are factitious; which are those which the mind forms, by uniting and assembling the ideas which it already had; and these are called complex. But Mr Locke seems to have put this matter out of dispute; having made it appear, that all our ideas are owing to our senses; and that all innate, created, and factitious ideas, are mere chimeras.
Our mind, he shows, has not absolutely any ideas besides those presented to it by the senses, and those which it forms by its own operations on those others which the senses furnish; so that a man, destitute of one of his senses, would never have any idea belonging to that sense; and, supposing him destitute of all the senses, he would never have any idea at all: external objects having no other way of producing ideas in him, but by means of sensation, he would have no idea, not even of reflection; because, in wanting all sensation, he wants that which would excite in him the operations of his mind, which are the objects of his reflection.
It is plain, therefore, there is no innate idea; no general truth, or first principle, inherent in the soul, and created with it; no immediate object of the mind, before it had perceived external objects by means of the senses, and reflected on that perception. Those ideas only seem to be innate, because we find we have them as soon as we come to the use of reason; but they are, in effect, what we formed from the ideas wherewith the mind was insensibly filled by the senses. Thus, when the mind is employed about sensible objects, it comes by the ideas of bitter, sweet, yellow, hard, &c. which we call sensation; and, when employed about its own operations, perceiving and reflecting on them, as employed about the ideas before got by sensation, we get the ideas of perception, thinking, doubting, willing, &c. which we call inward sensation, or reflection; and these two, viz. external material
things as the objects of sensation, and the operations of our own minds as the objects of reflection, are the only originals whence all our ideas have their rise. When we have considered these, and their several modes and combinations, we shall find, that they contain our whole stock of ideas, inasmuch that the understanding does not seem to have the least glimmering of any ideas, that it did not receive from one of those sources.
And thus far the mind appears merely passive, as not having it in its power to choose whether it will have these first beginnings, or materials of knowledge, or not. For the objects of sense will obtrude their ideas upon the mind; and the operations of the mind will not let us be without some (however obscure) notion of them.
The origin of our ideas and notions is a perplexed question, and not at all cleared up by the labours of metaphysicians. As to ideas of sense, some philosophers have pretended, that bodies acting or pressing upon our nerves, or putting the animal-spirits in motion, produce sensations; but as the motion communicated to the nerves or spirits has nothing in common either with the thing or body moving, or with the idea excited in the mind, and that we do not conceive the least relation between the motion of the nerves or spirits and the production of an idea; to say that the motion of, or impression upon, the nerves or animal-spirits is the cause of ideas, is explaining nothing at all.
The species emitted by objects, and the formation of ideas by the soul itself, are not more clear. As to innate ideas, it is true indeed, that the arguments of those who maintain them, have been refuted by Mr Locke; but when he goes farther, and denies innate ideas, his arguments have been thought by some not to be conclusive.
Dr Price, in his Inquiry into the Original of our Ideas, has taken occasion to remark, that the system of Mr Locke, which ascribes all our ideas to sensation and reflection, is materially defective; for, if by sensation we understand the effects arising from the impressions made on our minds by external objects, and by reflection the notice which the mind takes of its own operations, it will be impossible to drive some of the most important of our ideas from them. This excellent reasoner observes, that the power within us that understands, the intuition of the mind, or the faculty in it that discerns truth, that views, compares, and judges of all ideas and things, is a spring of new simple ideas, or original, primary, and uncomposed perceptions of the mind. To this source he refers our ideas of the impenetrability and vis inertie of matter, substance, duration, space, infinity, necessity, contingency, possibility, impossibility, power, causation, &c. all our abstract ideas, and also our ideas of moral right and wrong, and of moral obligation. It is, he says, of the essence of these ideas to imply something true or false of an object, and that they by no means denote the manner in which we are affected by it; so that they cannot with any propriety be referred to that part of our constitution, which has been distinguished by the appellation of sense. Accordingly, our ideas may be divided, first, into those implying nothing real without the mind, or nothing real and true besides its own affections and passions: to which class we may refer the immediate effects of impressions on the bodily
senses, without supposing any previous ideas; as all tastes, smells, colours, &c. : and those that arise upon occasion only of other ideas; as the effects in us of considering, order, happiness, the beauties of poetry, painting, &c. Secondly, into those which are images of something distinct from sensation, or which imply real, independent of existence and truth; which may be subdivided into such as denote the real properties of external objects, and the actions and passions of the mind; and those which are derived immediately from intelligence. By the notices conveyed to the mind through the organs of the body, or its observation of the necessary attendants and concomitants of certain sensations and impressions, it perceives the figure, extension, motion, and other primary qualities of material substances; by contemplating itself, it perceives the properties of spiritual substances, volition, consciousness, memory, &c. To all these ideas it is essential that they have real, certain, invariable archetypes, actually existing, to which they are referred, and to which they are conformable. These ideas again become objects or archetypes to the intellective faculty; from whence arises a new set of ideas, which are the perceptions of this faculty, and represent not the mind's own affections, but necessary truth. Antecedently to these, whatever other ideas we may be furnished with, nothing is understood; whatever feeds or subjects of knowledge may be in the mind, nothing is known.
The system of Mr Locke, with regard to the origin of our ideas, has lately been attacked by Dr Reid and others; and it has been charged as the foundation of universal scepticism. Dr Reid objects to every system which supposes that the mind receives images of things from without by means of the senses, because sensations bear no resemblance to bodies, or any of their qualities. With regard to extension, figure, motion, &c. he says, if they are not ideas of sensation, nor like to any sensation, then the ideal system is a rope of sand, and all the laboured arguments of the sceptical philosophy against a material world, and against the existence of every thing but impressions and ideas, proceed upon a false hypothesis. To this objection it has been replied, that ideas are only in a figurative sense the images of external things; that certain impressions are conveyed to the mind by means of the organs of sense, and their corresponding nerves, between which, and the sensations existing in the mind, there is a real and necessary, though at present an unknown connection; and that the same reasoning would lead him to deny that sounds are produced by bodies striking against one another, because he can perceive no proper resemblance between the cause and the effect.
Dr Reid further objects to the notion generally received among philosophers, that the images of external objects are conveyed by the organs of sense to the brain, and there perceived by the mind. But from this objection it might be inferred, that the whole system of our senses, nerves, and brain, is of no real use whatever; because it is impossible to say how they act upon the mind, or the mind upon them.
It is also objected, that Mr Locke's division of ideas into those of sensation, and those of reflection, is contrary to all the rules of logic; because the second member of the division includes the first. For can we,
says he, form clear and just notions of our sensations any other way than by reflection? Sensation is an operation of the mind, of which we are conscious, and we get the notion of it by reflecting upon that which we are conscious of. In like manner, doubting and believing are operations of the mind, whereof we are conscious, and we get the notion of them by reflecting upon what we are conscious of. The ideas of sensation, therefore, are ideas of reflection, as much as the ideas of doubting or believing, or any other idea whatsoever. But it has been alleged, that the author confounds the ideas of sensation with the idea of sensation itself, which is, without doubt, of the same class with the ideas of doubting, &c. as Mr Locke would have allowed. But the ideas belonging to the class of sensation do not require any scientific knowledge of that power, or any reflection upon it. If this were the case, brute animals, having no proper ideas of reflection, could have no ideas of sensation; and the case would be the same with the bulk of mankind. In another place, Dr Reid acknowledges, that human beings may have ideas of mere sensation some time before they discover any power of reflection, and that this power may discover itself and come into exercise afterwards.
Dr Beattie, Dr Oswald, and others, have pursued and extended the same kind of reasoning against the principles of Mr Locke; and alleged, that Berkeley's reasoning against the existence of a material world, and Hume's reasoning against the existence both of soul and body, are deduced from Locke's Essay, and the Principia of Des Cartes.
In opposition to this system, Dr Reid, and those who have adopted his theory, have recurred to certain instinctive principles; alleging that our perceptions necessarily imply the belief of the present existence of external objects; and that the real, separate, and independent existence of matter, is believed, not because it can be proved by argument, but because the constitution of our nature is such, and we must believe it; and that we cannot, in our own minds, separate the belief of external objects from our sensations. However, it has been urged by an ingenious writer, that Mr Locke's doctrine is not so favourable to Mr Berkeley's theory as Dr Reid's; and that a system which ascribes our primary mental operations to mere constitution and feeling, is more favourable to scepticism than that in the room of which it is substituted. According to Mr Hume's system, all perceptions are either impressions or ideas, and it is not possible for us so much as to conceive any thing specifically different from ideas and impressions; and since all ideas are copied from impressions, we can, therefore, have no idea or conception of any thing of which we have not received an impression. No man can have any idea of power or energy, because he has never received any impression of it; and for the same reason no man can have any idea of self. What we call a mind is nothing but a bundle or collection of different perceptions, which succeed each other with inconceivable rapidity, and are in a perpetual flux and movement. There is properly, says Mr Hume, no simplicity in the mind at one time, nor identity at different times, whatever natural propensity we may have to imagine that simplicity and identity. They are the successive perceptions only that constitute the mind: so that there
there is nothing in the universe but impressions and ideas; all possible perceptions being comprehended in those two classes. Consequently, this philosophy, excluding body and mind, admits of no existence whatsoever, not even of a percipient being to be the subject of these perceptions. To the same purpose Dr Reid observes, that, according to Mr Locke's system, ideas being the only objects of thought, and having no existence but when we are conscious of them, it necessarily follows, that there is no object of our thought which can have a continued and permanent existence. Body and spirit, cause and effect, time and space, to which we were wont to ascribe an existence independent of our thought, are all turned out of existence by this short dilemma. Either these things are ideas of sensation or reflection, or they are not: if they are ideas of sensation or reflection, they can have no existence but when we are conscious of them: if they are not ideas of sensation or reflection, they are words without any meaning. To which we shall only reply, that we have the same reason to believe, that mind exists as that body exists; since it is only by that name that we distinguish the subject of certain powers or properties, of which we are conscious, as perception, memory, will, &c. and we have just the same reason to believe the identity of an idea as that of any external body, or that of our own minds.
Those who wish to be farther acquainted with the controversy relating to the nature and origin of our ideas, must be referred to Hume's Treatise of Human Nature, vol. i. p. 123, &c. 282, &c. 434, &c. Reid's Inquiry into the Human Mind, passim. Beattie's Essay on Truth, part ii. chap. 2. Priestley's Examination of Reid, Beattie, &c. passim.