Abstract

Roughly characterized, solipsism is the skeptical thesis that there is no reason to think that anything exists other than oneself and one’s present experience. Since its inception in the reflections of Descartes, the thesis has taken three broad and sometimes overlapping forms: Internal World Solipsism that arises from an account of perception in terms of representations of an external world; Observed World Solipsism that arises from doubts as to the existence of what is not actually present sensuously in experience; Unreal World Solipsism that arises from doubts as to the reality of the perceived world. This book attempts to give a rationally warranted refutation of all three forms. Over time, a vast number of putative rebuttals of solipsism have been proposed. The first half of the book clears the terrain for more productive investigation by showing in detail how each of these various responses fails. Among the simpler of such responses is the claim to have knowledge and certainty about everyday matters (Moore, Austin, Quinton, Pollock). Another is to appeal to pragmatic considerations dictated by the fact of one’s living in the world (Wittgenstein, Rescher, Ayer, Will, Strawson). Yet another is to undermine the skeptical thesis by applying it to itself (Plato, Hume, Russell, Johnson). All of these simpler approaches are found to be inadequate or irrelevant (Chapters 2 and 3). Other responses are more complex in that they presuppose certain basic positions with regard to the nature of cognition, meaning, language, or thought. Consequently, showing how they fail often involves showing the falsity of their underlying views. One such approach maintains that any empirical enquiry presupposes the existence of material objects (Neurath, Wittgenstein, Sellars, Quine, Gurwitsch, Williams, Rorty, BonJour), and that consequently solipsism is a problem peculiar to a mistaken foundationalist epistemology that purports to derive all warranted belief about the world from sensuous data. However, on examination, the various lines of reasoning advanced are found to be fallacious (Chapter 4). A closely-related approach is to claim that any empirical enquiry presupposes background truths, and that consequently solipsism is parasitic in the sense that it is based on truths that it purports to deny (Heidegger, Wittgenstein, Sellars, Quine). Such a self-contradictory situation is shown to obtain for only one form of solipsism, representational solipsism with its classical external world problem dating back to Descartes (Chapter 5). Another approach is to appeal to linguistic considerations in order to level charges of meaninglessness against solipsism (Wittgenstein, Austin, Ryle, Putnam, Clarke, Stroud). However, the charges are easily shown to be unwarranted (Chapter 6), a conclusion subsequently corroborated by a briefly sketched first-person account of meaning (Chapter 7). A further approach is to claim that all philosophical thinking must involve linguistic concepts, that language is intersubjective and tied to objects, and hence that solipsism is conceptually parasitic, and hence calls into question a conceptual scheme that it presupposes (Kant, Strawson, Wittgenstein, Sellars, Quine, Rorty). However, it may be shown that language is not incorrigibly wedded to objects, and in revised form it may be used to state solipsistic theses (Chapter 8). This conclusion is further supported by a refutation of various arguments against the possibility of private language (Wittgenstein, Sellars, Goodman, Rorty, Gadamer), as well as by the empirical evidence of everyday thinking that commonly takes place without reliance on the structures of public language (Chapter 9). The final chapters are more directly constructive. Following foundationalist procedure, a survey is undertaken of the sensuous data of first-person experience in its various modalities and their interrelationships (Chapter 10). An account is given of the bodily nature of the experiencing subject or self that feels, that wills, and that thinks, as well as of the spontaneity of the self or its capacity for free choice (Chapter 11). Rational warrant is then provided for thinking that items randomly perceived through a subject’s spontaneity or free will, continue to exist when unperceived, thus refuting forms of Observed World Solipsism that deny the existence of unperceived objects (Chapter 12). Finally, it is argued with regard to Unreal World Solipsism that while the scenarios it proposes cannot be dismissed as impossible, the absence of any supporting evidence whatever in their favor makes the espousal of any of them both arbitrary and an irrational leap (Chapter 13).