Idea

The word “idea” carries a longer history than almost any other term in philosophy, and few words have changed their meaning so completely while remaining in constant use. In the Harvard Classics it names, at one extreme, the eternal and changeless realities which Plato’s Socrates holds to be more truly real than anything the senses show. At the other, it names the faint copies of sensation that Hume finds in every mind. Between these lie the patterns in the mind of God, Berkeley’s claim that the things we see and touch are themselves ideas, and the ruling idea which Emerson and Carlyle think forms a man or moves a nation. The idea is a great idea for these books because nearly every inquiry into knowledge, art, education or reform has to say what ideas are, where they come from, whether they can be general, and what power they hold over conduct. The quarrels over these questions run from the prison cell of the *Phaedo* to the lecture halls of nineteenth-century New England.

The first position is Plato’s, and it is set out most fully in the *Phaedo*. Socrates observes that equal sticks and stones are not equality itself. The idea of equality is distinct from them, though it is called to mind on occasion of seeing them¹. Material equals fall short of that standard and only approximate it². Since we recognize the shortfall, we must have known the standard before. So beauty, goodness, justice, holiness and equality are essences the soul knew before birth³. Plato binds the ideas and the soul’s preexistence tightly together: if these absolutes exist, the soul existed before the body, and the two doctrines stand or fall together⁴. Later in the dialogue Socrates describes his turn from the study of physical causes to the ideas, so as not to blind the soul by looking at things through the senses⁵. He assumes absolute beauty, goodness and greatness, and holds that a thing is beautiful only by participating in absolute beauty⁶. His hearers agree that the ideas exist and that other things take their names from partaking of them⁷. Each idea keeps its own character absolutely: greatness itself cannot become small, and when its opposite approaches it either withdraws or perishes⁸.

Christian and later writers carried the Platonic doctrine into a theological setting, placing the ideas in the divine mind. Augustine reports that numbers and geometrical lines are known inwardly, without bodily images⁹. Dante sees everything mortal and immortal as the radiance of the idea which the Father engenders through love¹⁰. Raleigh distinguishes the eternal Platonic pattern of the world from its creation in time¹¹. Kant treats the intelligible world in a far more guarded way. For him it is an idea, but a well-founded one, which marks the limits of sensibility rather than a realm we behold¹². Thus the idea has already moved from an object the soul contemplates toward a notion by which reason marks the bounds of its own knowledge.

Berkeley completes the reversal. In the *Three Dialogues* Philonous holds that whatever is immediately perceived is an idea and cannot exist outside the mind^13,14. Merely to conceive a thing is to make it an idea in the one who conceives it¹⁵. Apart from spirits, all we know are our own ideas¹⁶. He refuses even Malebranche’s middle course of abstract general ideas, insisting that the things perceived are themselves ideas existing only in a mind¹⁷. To the charge that this turns the world into fiction, he replies that only perceiving things and perceived things exist, and every perceived thing is perceived by some mind¹⁸. Sensible things are ideas because they are the immediate objects of understanding, not because they are chimeras, and the dispute is finally about a name¹⁹. Natural science survives this change. Phenomena are ideas, and to explain them is to show the order in which they are imprinted on us²⁰. That order points to its cause, since only a being with knowledge and will can produce ideas in minds²¹.

The heart of Berkeley’s case is an attack on the view that ideas are pictures of external originals. Hylas proposes that ideas represent things outside the mind²². Philonous asks how we could ever tell a true copy from a false one, when we never see the original²³. He then presses the decisive point. Nothing can be like an idea except another idea, and so an unperceiving material substance can contain neither an idea nor the likeness of one^24,25. Ideas cannot have absolute existence outside all minds, nor resemble originals no one perceives²⁶. Berkeley does not wholly abandon the notion of an archetype, however. He relocates it, suggesting that an external archetype may be supposed in the divine mind which comprehends all things²⁷. In this way Berkeley comes round, by a modern road, to something like the divine patterns of the older tradition.

Representation fails in another direction too. Ideas, Berkeley says, are passive and inert, so none can represent the active God²⁸. For the same reason no inert idea can represent spirits, which are active²⁹. We have a “notion” of spirit, then, though no idea of it³⁰. Hobbes reaches a comparable result by a different route. A blind man warmed by a fire conceives that something warms him without having any image of it. In the same way, men conceive a cause of the world without having an idea of God³¹. Hobbes and Berkeley agree that our knowledge of the divine outruns our images, though they draw very different conclusions from this.

The origin of ideas was the great dispute of the seventeenth and eighteenth centuries. Descartes asks where his idea of a perfect nature came from. He could have produced the ideas of sky, earth and heat himself, but not this one³². Examining that idea, he finds that existence belongs to the essence of a Perfect Being³³. Voltaire reports the controversy as an observer sympathetic to the English. Descartes admitted innate ideas³⁴, and with Malebranche held that the soul has innate ideas and always thinks. Locke, by contrast, traced the understanding’s progress from infancy³⁵, destroyed innate ideas, and showed that ideas come by the senses³⁶. Voltaire’s Quaker, curiously, sides with Malebranche, arguing that ideas pour into the mind involuntarily and are therefore given by God³⁷. Locke himself, in his writing on education, assumes the empiricist account, observing that ideas of visible things come from the things or their pictures, not from the sounds of words³⁸. Rousseau holds a middle position. He grants that all animals have ideas because they have senses, so that man differs from them in degree³⁹. Yet his Savoyard Vicar rejects the view that everything in the mind is acquired from experience⁴⁰. Ideas come from without, he says, but sentiments, such as those of conscience, come from within⁴¹. The innate, for Rousseau, survives as feeling rather than as idea.

Hume gives the empiricist side its most rigorous form. He divides perceptions into lively impressions and fainter thoughts or ideas⁴². Every idea is a copy of a prior impression, and the imagination, for all its apparent liberty, can only compound, transpose, enlarge or diminish what sense and experience supply^43,44. He admits a single counter-instance: a person might supply a missing shade of blue never seen. He treats it as too singular to alter the general maxim⁴⁵. The innate-ideas dispute, he thinks, is cleared up by this doctrine. If “innate” means original and uncopied, then impressions are innate and ideas are not^46,47. The doctrine also becomes a critical test. An obscure idea is clarified by producing the impression from which it derives⁴⁸, and where no impression can be found, there is no idea⁴⁹. Hume applies this test to power. He considers the claim that power is an idea of reflection copied from an inner impression⁵⁰. Finding no impression of necessary connection, he concludes that the words power and connexion seem, as commonly used, to be without meaning⁵¹. Even the idea of extension he derives wholly from sight and feeling⁵². Where Descartes found in the idea of perfection proof of God, Hume’s test leaves several metaphysical words without content.

Hume also asks how ideas are joined. He finds three principles of association: resemblance, contiguity, and cause and effect⁵³. He illustrates them in turn. A picture leads the mind to its original, mention of one apartment to the next, a wound to thoughts of pain⁵⁴. Pascal, earlier and in another spirit, doubts that the mind receives ideas passively at all. We never take ideas in their purity, he says, but stamp them with our composite nature of soul and body⁵⁵. We assume without proof that all men conceive things alike⁵⁶. The same thought bears different fruit in different minds, like a seed transplanted, and originality lies in developing its consequences⁵⁷. Hume describes mechanisms that operate in every mind alike, while Pascal attends to the individual character of each mind. The two accounts point to a question neither settles: whether an idea is the same in every mind that holds it.

Berkeley and Hume agree on one point that divides them from much of the tradition: the denial of abstract ideas. Philonous doubts that extension and motion can be conceived stripped of all sensible qualities⁵⁸. He challenges Hylas to frame such an idea, and Hylas cannot⁵⁹. No one can conceive a figure apart from some size and other sensible qualities⁶⁰, nor entity apart from all particulars⁶¹. Matter in its indefinite sense therefore contains no idea at all⁶². Hume follows this line. Ideas of quantity are particular, supplied by sense and imagination, and for that reason are not infinitely divisible⁶³. Rousseau reaches a different view. General ideas, he holds, are purely intellectual. Imagination can only make them particular, which is why no one can picture a tree or a triangle in general⁶⁴. Abstraction is real but unnatural and painful, which is why words like adjectives were slow to form among early men⁶⁵. Bacon warns that the primary notions the mind passively absorbs are confused and abstracted from facts too hastily⁶⁶. Schiller insists that a pure rational idea of the beautiful, reached by abstraction, is needed to judge particular cases⁶⁷. All agree that abstraction is difficult; they disagree over whether the difficulty shows a limit of the mind or the very nature of thinking.

If general ideas are doubtful, what do general words signify? Burke answers boldly. Compound abstract words such as virtue and honour raise no precise ideas, and analysis dissolves them into simpler notions⁶⁸. Words often act on us without presenting any images⁶⁹. A man may hear words and use them again without any idea of the things they name⁷⁰. In conversation and reading, words stand in for ideas, and images are seldom excited⁷¹, even when the talk is of particular beings⁷². Yet words attach affections to ideas that present no distinct image, which is the source of their power in poetry⁷³. Burke treats words without images as a source of strength. Others treat words without ideas as a failing. Rousseau’s Vicar complains that phrases like universal force and necessary motion convey no meaning⁷⁴. Montaigne says that those who cannot express themselves have only shapeless conceptions which they themselves do not understand⁷⁵.

The later essayists turn from the anatomy of ideas to their power. Channing holds that a great mind is formed by a few great, comprehensive ideas rather than a mass of loose details, so that the quality of knowledge, not its quantity, gives it dignity⁷⁶. The idea of God he calls the first of these⁷⁷. Ideas like freedom and immortality are mightier than the passions, and they form heroes and martyrs⁷⁸. Such ideas come as glimpses that need reflection, and without it they dazzle and unbalance the mind⁷⁹. Seized by a people, a great idea can regenerate a community⁸⁰. Carlyle sees each polity as the embodiment of an Idea that prescribes its tendencies⁸¹. He speaks of the great man as possessed by an idea as by a divine fire, Napoleon’s being careers open to talent⁸². Emerson makes the idea the key to every man, the thought by which he classifies facts, which only a new idea can reform⁸³. Culture is the predominance of an idea that draws institutions after it⁸⁴. Ideas of reform spread through all hearts, and when facts grow false the scholar retreats to ideas⁸⁵. History itself, Emerson writes, depends on the ideas that arise in men’s minds⁸⁶, and he prizes the mystic lover of ideas over the merely correct writer⁸⁷. In these essays the Platonic sense returns in a moral and social form: the idea is a standard that judges and moves the actual.

In art the idea is the conception that precedes the work. Sidney places the artificer’s skill in the idea or fore-conceit of the work, which the poet delivers as he has imagined it⁸⁸. Milton calls his plan of education an idea long present to his mind⁸⁹. Dryden holds that even when Raphael paints what exists in nature, the idea in his imitation is Raphael’s own⁹⁰. Lamb argues that a stage performance, far from realizing an idea, lowers a fine vision to actuality⁹¹. Arnold puts it most strongly: for poetry the idea is everything, emotion attaches to the idea, and the idea is the fact⁹².

Finally, the teachers ask how clear ideas are formed. Locke counsels giving children one simple idea at a time, making sure it is understood before adding the next⁹³. He also wants pupils to form distinct ideas and to avoid verbal distinctions where no real difference of ideas exists⁹⁴. Here the empiricist theory of origins becomes a method of teaching.

Several questions remain open across these texts. One is whether the idea is a reality the mind discovers, as Plato held, or a content the mind possesses, as Berkeley and Hume held. Another is whether anything in the mind is innate, whether ideas or, as Rousseau thought, sentiments. A third is whether abstraction is impossible, painful but necessary, or the proper work of reason. The last is whether words can mean without ideas, or move without images. The essayists’ faith that ideas transform persons and peoples assumes that ideas are more than faint copies of sensation. These books leave unresolved whether that faith can be reconciled with Hume’s analysis.