idealism the philosophical doctrine that reality is somehow mind-correlative or mind-coordinated – that the real objects constituting the ‘external world’ are not independent of cognizing minds, but exist only as in some way correlative to mental operations. The doctrine centers on the conception that reality as we understand it reflects the workings of mind. Perhaps its most radical version is the ancient Oriental spiritualistic or panpsychistic idea, renewed in Christian Science, that minds and their thoughts are all there is – that reality is simply the sum total of the visions (or dreams?) of one or more minds.
A dispute has long raged within the idealist camp over whether ‘the mind’ at issue in such idealistic formulas was a mind emplaced outside of or behind nature (absolute idealism), or a nature-pervasive power of rationality of some sort (cosmic idealism), or the collective impersonal social mind of people in general (social idealism), or simply the distributive collection of individual minds (personal idealism). Over the years, the less grandiose versions of the theory came increasingly to the fore, and in recent times virtually all idealists have construed ‘the minds’ at issue in their theory as separate individual minds equipped with socially engendered resources.
There are certainly versions of idealism short of the spiritualistic position of an ontological idealism that (as Kant puts it at Prolegomena, section 13, n. 2) holds that ‘there are none but thinking beings.’ Idealism need certainly not go so far as to affirm that mind makes or constitutes matter; it is quite enough to maintain (e.g.) that all of the characterizing properties of physical existents resemble phenomenal sensory properties in representing dispositions to affect mind-endowed creatures in a certain sort of way, so that these properties have no standing without reference to minds. Weaker still is an explanatory idealism which merely holds that an adequate explanation of the real always requires some recourse to the operations of mind.
Historically, positions of the generally idealistic type have been espoused by numerous thinkers. For example, Berkeley maintained that ‘to be [real] is to be perceived’ (esse est percipi). And while this does not seem particularly plausible because of its inherent commitment to omniscience, it seems more sensible to adopt ‘to be is to be perceivable’ (esse est percipile esse). For Berkeley, of course, this was a distinction without a difference: if something is perceivable at all, then God perceives it. But if we forgo philosophical reliance on God, the matter looks different, and pivots on the question of what is perceivable for perceivers who are physically realizable in ‘the real world,’ so that physical existence could be seen – not so implausibly – as tantamount to observability-in-principle. The three positions to the effect that real things just exactly are things as philosophy or as science or as ‘common sense’ takes them to be – positions generally designated as Scholastic, scientific, and naive realism, respectively – are in fact versions of epistemic idealism exactly because they see reals as inherently knowable and do not contemplate mind-transcendence for the real. Thus, the thesis of naive (‘commonsense’) realism that ‘External things exist exactly as we know them’ sounds realistic or idealistic according as one stresses the first three words of the dictum or the last four. Any theory of natural teleology that regards the real as explicable in terms of value could to this extent be counted as idealistic, in that valuing is by nature a mental process. To be sure, the good of a creature or species of creatures (e.g., their well-being or survival) need not be something mind-represented. But nevertheless, goods count as such precisely because if the creatures at issue could think about it, they would adopt them as purposes. It is this circumstance that renders any sort of teleological explanation at least conceptually idealistic in nature. Doctrines of this sort have been the stock-in-trade of philosophy from the days of Plato (think of the Socrates of the Phaedo) to those of Leibniz, with his insistence that the real world must be the best possible. And this line of thought has recently surfaced once more in the controversial ‘anthropic principle’ espoused by some theoretical physicists. Then too it is possible to contemplate a position along the lines envisioned in Fichte’s Wissenschaftslehre (The Science of Knowledge), which sees the ideal as providing the determining factor for the real. On such a view, the real is not characterized by the science we actually have but by the ideal science that is the telos of our scientific efforts. On this approach, which Wilhelm Wundt characterized as ‘ideal-realism’ (Idealrealismus; see his Logik, vol. 1, 2d ed., 1895), the knowledge that achieves adequation to the real (adaequatio ad rem) by adequately characterizing the true facts in scientific matters is not the knowledge actually afforded by present-day science, but only that of an ideal or perfected science.
Over the years, many objections to idealism have been advanced. Samuel Johnson thought to refute Berkeley’s phenomenalism by kicking a stone. He conveniently forgot that Berkeley goes to great lengths to provide for stones – even to the point of invoking the aid of God on their behalf. Moore pointed to the human hand as an undeniably mind-external material object. He overlooked that, gesticulate as he would, he would do no more than induce people to accept the presence of a hand on the basis of the handorientation of their experience. Peirce’s ‘Harvard Experiment’ of letting go of a stone held aloft was supposed to establish Scholastic realism because his audience could not control their expectation of the stone’s falling to earth. But an uncontrollable expectation is still an expectation, and the realism at issue is no more than a realistic thought-exposure.
Kant’s famous ‘Refutation of Idealism’ argues that our conception of ourselves as mindendowed beings presupposes material objects because we view our mind-endowed selves as existing in an objective temporal order, and such an order requires the existence of periodic physical processes (clocks, pendula, planetary regularities) for its establishment. At most, however, this argument succeeds in showing that such physical processes have to be assumed by minds, the issue of their actual mind-independent existence remaining unaddressed. (Kantian realism is an intraexperiential ’empirical’ realism.)
It is sometimes said that idealism confuses objects with our knowledge of them and conflates the real with our thought about it. But this charge misses the point. The only reality with which we inquirers can have any cognitive commerce is reality as we conceive it to be. Our only information about reality is via the operation of mind – our only cognitive access to reality is through the mediation of mind-devised models of it.
Perhaps the most common objection to idealism turns on the supposed mind-independence of the real: ‘Surely things in nature would remain substantially unchanged if there were no minds.’ This is perfectly plausible in one sense, namely the causal one – which is why causal idealism has its problems. But it is certainly not true conceptually. The objector has to specify just exactly what would remain the same. ‘Surely roses would smell just as sweet in a minddenuded world!’ Wel. . . yes and no. To be sure, the absence of minds would not change roses. But roses and rose fragrance and sweetness – and even the size of roses – are all factors whose determination hinges on such mental operations as smelling, scanning, measuring, and the like. Mind-requiring processes are needed for something in the world to be discriminated as a rose and determined to bear certain features. Identification, classification, property attribution are all required and by their very nature are all mental operations. To be sure, the role of mind is here hypothetical. (‘If certain interactions with duly constituted observers took place, then certain outcomes would be noted.’) But the fact remains that nothing could be discriminated or characterized as a rose in a context where the prospect of performing suitable mental operations (measuring, smelling, etc.) is not presupposed. Perhaps the strongest argument favoring idealism is that any characterization of the real that we can devise is bound to be a mind-constructed one: our only access to information about what the real is is through the mediation of mind. What seems right about idealism is inherent in the fact that in investigating the real we are clearly constrained to use our own concepts to address our own issues – that we can learn about the real only in our own terms of reference. But what seems right about realism is that the answers to the questions we put to the real are provided by reality itself – whatever the answers may be, they are substantially what they are because it is reality itself that determines them to be that way. See also BERKELEY , FICHTE, HEGEL, KANT, METAPHYSIC. N.R.