This paper investigates Hume's theory of the perception of spatial magnitude or size as developed in the _Treatise<D>, as well as its relation to his concepts of space and geometry. The central focus of the discussion is Hume's espousal of the 'composite' hypothesis, which holds that perceptions of spatial magnitude are composed of indivisible sensible points, such that the total magnitude of a visible figure is a derived by-product of its component parts. Overall, it will be argued that a straightforward (...) reading of this hypothesis fails to do full justice to the complexity of Hume's theory of spatial perception and geometry, and that a more adequate treatment must also admit an important role for the more direct process of spatial magnitude perception which he dubs 'intuition'. (shrink)

A polemical account of Australian philosophy up to 2003, emphasising its unique aspects (such as commitment to realism) and the connections between philosophers' views and their lives. Topics include early idealism, the dominance of John Anderson in Sydney, the Orr case, Catholic scholasticism, Melbourne Wittgensteinianism, philosophy of science, the Sydney disturbances of the 1970s, Francofeminism, environmental philosophy, the philosophy of law and Mabo, ethics and Peter Singer. Realist theories especially praised are David Armstrong's on universals, David Stove's on logical probability (...) and the ethical realism of Rai Gaita and Catholic philosophers. In addition to strict philosophy, the book treats non-religious moral traditions to train virtue, such as Freemasonry, civics education and the Greek and Roman classics. (shrink)

The main problem of this study is David Hume’s (1711-76) view on Metaphysical Realism (there are mind-independent, external, and continuous entities). This specific problem is part of two more general questions in Hume scholarship: his attitude to scepticism and the relation between naturalism and skepticism in his thinking. A novel interpretation of these problems is defended in this work. The chief thesis is that Hume is both a sceptic and a Metaphysical Realist. His philosophical attitude is to suspend his judgment (...) on Metaphysical Realism, whereas as a common man he firmly believes in the existence of mind-independent, external, and continuous entities. Therefore Hume does not have any one position; accordingly, a form of “no one Hume” interpretation (Richard Popkin, Robert J. Fogelin, Donald L.M. Baxter) is argued for in the book. The key point in this distinction is the temporal difference between Hume’s philosophical and everyday views. It is introduced in order to avoid attributing a conscious contradiction to him (a problem which has not attracted enough attention in the literature). The method of the work is modelled on Peter Millican’s work on Hume and induction. The approach to the main problem is to study the two “profound” arguments against the senses that Hume presents in the Section 12 of An Enquiry concerning Human Understanding (1748). These arguments are first reconstructed in detail resulting in Millican-type diagrams of them and then Hume’s endorsement of them is established on the basis of the diagrams. The first profound argument concludes that Metaphysical Realism and thus any Realistic theory of perception is unjustified as well as the existence of God and the soul. The second argument goes further having first conceptual conclusion: the very notions of Real entitity, material substance, and bodies are completely out of the reach of the faculty of understanding. Therefore they ought to be rejected according to Hume. This is a consequence of the consistent use of the Humean faculty of reason: idea-analysis and inductive inference. The second profound argument thus concludes that believing in Metaphysical Realism is inconsistent with the rational attitude that is to refrain from this belief. Hence, if we attributed both of them to Hume, we would end up with a great philosopher who embraces a manifest contradiction. The study is finished by arguing that this sceptical and Metaphysically Realistic interpretation concurs well with (1) Hume’s professed Academical philosophy and (2) project of the science of human nature. (1) According to Hume, Academical philosophy is in the first place diffidence, modesty, and uncertainty including suspension on certain issues. Secondly, it is restriction of the range of topics for which experience can provide a standard of truth. This kind of empiricist epistemological realism is coherent with the sceptical attitude on Metaphysical Realism because the latter does not rule out inter-subjective consensus on what we experience. (2) Suspension of judgment on Metaphysical Realism coheres with the mind-dependency of the objects of Hume’s science of human nature: the understanding, passions, morals, aesthetics, politics, and the human culture in all of its manifestations. Although the study takes the first Enquiry to be Hume’s authorised word on the understanding, his juvenile work A Treatise of Human Nature (1739-40) is argued to support this “no one Hume” interpretation. Hume’s other works are also discussed when needed. (shrink)

Hume’s discussion of space, time, and mathematics at T 1.2 appeared to many earlier commentators as one of the weakest parts of his philosophy. From the point of view of pure mathematics, for example, Hume’s assumptions about the infinite may appear as crude misunderstandings of the continuum and infinite divisibility. I shall argue, on the contrary, that Hume’s views on this topic are deeply connected with his radically empiricist reliance on phenomenologically given sensory images. He insightfully shows that, working within (...) this epistemological model, we cannot attain complete certainty about the continuum but only at most about discrete quantity. Geometry, in contrast to arithmetic, cannot be a fully exact science. A number of more recent commentators have offered sympathetic interpretations of Hume’s discussion aiming to correct the older tendency to dismiss this part of the Treatise as weak and confused. Most of these commentators interpret Hume as anticipating the contemporary idea of a finite or discrete geometry. They view Hume’s conception that space is composed of simple indivisible minima as a forerunner of the conception that space is a discretely (rather than continuously) ordered set. This approach, in my view, is helpful as far as it goes, but there are several important features of Hume’s discussion that are not sufficiently appreciated. I go beyond these recent commentators by emphasizing three of Hume’s most original contributions. First, Hume’s epistemological model invokes the “confounding” of indivisible minima to explain the appearance of spatial continuity. Second, Hume’s sharp contrast between the perfect exactitude of arithmetic and the irremediable inexactitude of geometry reverses the more familiar conception of the early modern tradition in pure mathematics, according to which geometry (the science of continuous quantity) has its own standard of equality that is independent from and more exact than any corresponding standard supplied by algebra and arithmetic (the sciences of discrete quantity). Third, Hume has a developed explanation of how geometry (traditional Euclidean geometry) is nonetheless possible as an axiomatic demonstrative science possessing considerably more exactitude and certainty that the “loose judgements” of the vulgar. (shrink)

Quantity is the first category that Aristotle lists after substance. It has extraordinary epistemological clarity: "2+2=4" is the model of a self-evident and universally known truth. Continuous quantities such as the ratio of circumference to diameter of a circle are as clearly known as discrete ones. The theory that mathematics was "the science of quantity" was once the leading philosophy of mathematics. The article looks at puzzles in the classification and epistemology of quantity.

Aristotelian, or non-Platonist, realism holds that mathematics is a science of the real world, just as much as biology or sociology are. Where biology studies living things and sociology studies human social relations, mathematics studies the quantitative or structural aspects of things, such as ratios, or patterns, or complexity, or numerosity, or symmetry. Let us start with an example, as Aristotelians always prefer, an example that introduces the essential themes of the Aristotelian view of mathematics. A typical mathematical truth is (...) that there are six different pairs in four objects: Figure 1. There are 6 different pairs in 4 objects The objects may be of any kind, physical, mental or abstract. The mathematical statement does not refer to any properties of the objects, but only to patterning of the parts in the complex of the four objects. If that seems to us less a solid truth about the real world than the causation of flu by viruses, that may be simply due to our blindness about relations, or tendency to regard them as somehow less real than things and properties. But relations (for example, relations of equality between parts of a structure) are as real as colours or causes. (shrink)

In many diagrams one seems to perceive necessity – one sees not only that something is so, but that it must be so. That conflicts with a certain empiricism largely taken for granted in contemporary philosophy, which believes perception is not capable of such feats. The reason for this belief is often thought well-summarized in Hume's maxim: ‘there are no necessary connections between distinct existences’. It is also thought that even if there were such necessities, perception is too passive or (...) localized a faculty to register them. We defend the perception of necessity against such Humeanism, drawing on examples from mathematics. (shrink)

The leaders of the Scientific Revolution were not Baconian in temperament, in trying to build up theories from data. Their project was that same as in Aristotle's Posterior Analytics: they hoped to find necessary principles that would show why the observations must be as they are. Their use of mathematics to do so expanded the Aristotelian project beyond the qualitative methods used by Aristotle and the scholastics. In many cases they succeeded.

Don Garrett, Cognition and Commitment in Hume's Philosophy, New York and Oxford, Oxford University Press, 1997, pp. xiv + 270, Hb 40.00 ISBN 0-19-509721-1.