First of all, he distinguishes between knowledge ofthings and knowledge of truths. Because, according to Russell, theacquaintance relation is a relation to individual things this questiontranslates into “what are the individual things we can beacquainted with?” Russell’s answer to this question isthat there are exactly two kinds of things we can be acquainted with,namely particulars, i.e., things that exist, and universals, i.e.,things that subsist (cf. (I, I, 5)In fact, we might suggest in closing, the main alternative to what isessentially the epistemological idealism of a great deal oftwentieth-century philosophy has not been any straightforward form ofrealism, but rather what might be called the “lifephilosophy” originally pioneered by Wilhelm Dilthey(1833–1916), then extensively developed by Martin Heidegger(1889–1976), and, without Heidegger’s political baggage,by the French philosopher Maurice Merleau-Ponty (1908–1961).
The main difference in this case is that Moore’sconception of what a concept is has virtually nothing to do with whatHegel means by “concept”, but this does not suffice toestablish ontological anti-idealism. (II, XXIII, 2)Yet Leibniz often seems to avert such a conclusion by appeal to hisidea of “preestablished harmony”, and this is possiblebecause he himself interprets this idea in two different ways. At the sametime, he does not seem to think that we are forced into skepticismabout either minds or external objects by his approach, that is, intoa position that there may really be minds and external objects but wecannot know that fact or their real qualities; yet he still has alingering worry that although there are psychological mechanismsleading us to form the fictions of minds and bodies beyondperceptions, we do not really know what we are talking about when wetalk about such things, and thus cannot even coherently doubt whetherwe have knowledge of them—our talk about them is explicable butmeaningless. According to Locke it is just a fact about human naturethat there are limits to the powers of the understanding. Given the fact that many also want to distinguish between realism,materialism, dogmatism, and empiricism, it is obvious that thinking ofthe meaning of “idealism” as determined by what it ismeant to be opposed to leads to further complexity and gives rise tothe impression that underlying such characterizations lies somepolemical intent.It may seem far-fetched to think of Friedrich Nietzsche(1844–1900) as an idealist. Descartes has largely fallen out of favor among modern philosophers, but we still read him due to his immense historical significance.The universe seems to me to be nearer to a great thought than to a great machine. If therefore the nature and the constitution ofsubstances both corporeal and spiritual are beyond our cognitive graspthen we should take this to be a hint that God has set limits to whatwe can know because he sees no reason for us to know everything. Afterdiscussing precursors, the entry focuses on the eighteenth-centuryversions of idealism due to Berkeley, Hume, and Kant, thenineteenth-century movements of German idealism and subsequentlyBritish and American idealism, and then concludes with an examinationof the attack upon idealism by Moore and Russell.As always when philosophy must decide between alternatives, there mustbe reasons or motives for deciding one way or the other.