Peter Millican

LOCKE famously defines knowledge as “the perception of the connexion and agreement, or disagreement and repugnancy of any of our Ideas” (Essay IV i 2), but his subsequent discussion significantly extends this somewhat vague and unclear definition. He starts by suggesting that knowledge always concerns one of four types of agreement or disagreement, namely “Identity, or Diversity”, “Relation”, “Co-existence, or necessary connexion”, and “real Existence”--his examples of the first two of these (perceiving the self-identity and distinctness of ideas, and the relations between ideas) fit relatively comfortably with his definition, but knowledge of “co-existence” (Locke instances the fixedness of gold and the magnetisability of iron) and “real existence” (for example of physical objects, or of God) both seem to involve the “agreement” of ideas with external things rather than merely amongst themselves.

Hume's essay on the credibility of miracle reports has always been controversial, with much debate over how it should be interpreted, let alone assessed. My aim here is to summarise what I take to be the most plausible views on these issues, both interpretative and philosophical, with references to facilitate deeper investigation if desired. The paper is divided into small sections, each headed by a question that provides a focus. Broadly speaking, §§1–3 and §20 are on Hume's general philosophical framework within which the essay is situated, §§4–11 and §19 are on Part 1, §12–18 are on Part 2, and the final three sections §§18–20 sum up my assessment of his arguments.

In October 1775, David Hume wrote to his printer William Strahan, requesting that an ‘Advertisement’ should be attached to remaining copies of the second volume of his Essays and Treatises on Several Subjects. This volume contained his two Enquiries, the Dissertation on the Passions, and The Natural History of Religion, and the Advertisement states that these works should ‘alone be regarded as containing his philosophical sentiments and principles’ (E 2). In the covering letter, Hume comments that this ‘is a compleat Answer to Dr Reid and to that bigotted silly Fellow, Beattie.’ (HL ii. 301). My aim here is to try to throw light on what Hume might have meant by this comment, and to assess to what extent it might have been justified.

The problem of the morality of abortion is one of the most complex and controversial in the entire field of applied ethics. It may therefore appear rather surprising that the most popular proposed “solutions” to it are extremely simple and straightforward, based on clear-cut universal rules which typically either condemn abortion severely in virtually every case or else deem it to be morally quite unproblematic, and hence permissible whenever the mother wishes. This polarised situation in the theoretical debate, however, is in clear contrast with the abortion law in many countries (including Britain), where abortions are treated very differently according to the stage of pregnancy at which they are carried out, so that early abortions are permitted relatively easily, whereas very late abortions are sanctioned only in exceptional cases. It seems likely, moreover, that in thus taking account of the time of an abortion, the law genuinely reflects the weight of public opinion - there may be no overall consensus on the underlying moral issues, but it does appear to be part of “commonsense” morality to accept that, whatever the ultimate rights and wrongs of abortion in general may be, at any rate abortion early in pregnancy is morally greatly preferable to late abortion. Let us call this “the developmental view”, since it holds that the moral gravity of abortion increases with the degree of development of the fetus.

The Christian tradition has always taken a generally negative view of abortion, but the moral basis and perceived implications of this negative view have varied greatly. In the early Church abortion and contraception were often seen as broadly equivalent, both involving interference with the natural reproductive process (and an association with sexual immorality which even led some to see contraception as the more sinful of the two). But the tendency to conflate abortion with contraception, and even on similar grounds with male masturbation, declined in the face of the biological discovery of the mother's role as more than just an incubator for the male "seed" - with the recognition of conception as a distinct and crucial event, abortion became generally seen as morally far more serious than contraception, potentially involving threat to an innocent life and therefore, arguably, equivalent to homicide. When seen as homicide, abortion has naturally been subject to an almost total prohibition, the only generally agreed exception being where it is necessary to save the mother's life. Within the Roman Catholic communion, moreover, even this exception has tended to be countenanced only when sanctioned by the doctrine of double effect - where the abortion is not directly intended, but is only a foreseen but unintended consequence of a surgical intervention whose primary intention is to save the mother's life (e.g. the removal of a cancerous uterus or of a fallopian tube containing an ectopic pregnancy).

Yujin Nagasawa accuses me of attributing to Anselm a principle (the 'principle of the superiority of existence', or PSE) which is not present in his text and which weakens, rather than strengthens, his Ontological Argument. I am undogmatic about the interpretative issue, but insist on a philosophical point: that Nagasawa's rejection of PSE does not help the argument, and appears to do so only because he overlooks the same ambiguity that vitiates the original. My conclusion therefore remains: that the fatal flaw in Anselm's argument—as in many other variants—is a relatively shallow ambiguity rather than a deep metaphysical mistake

The overall aim of this thesis is to understand Hume’s famous argument concerning induction, and to appraise its success in establishing its conclusion. The thesis accordingly falls into two main parts, the first being concerned with analysis and interpretation of the argument itself, and the second with investigation of possible responses to it. Naturally the argument’s interpretation strongly constrains the range of possible replies, and indeed the results of Part I indicate that the only kind of strategy which stands much prospect of defeating Hume’s argument is one based on a priori probabilistic reasoning – hence the overwhelming majority of Part II is devoted to a thorough investigation of this approach.

Any argument which attempts to prove God's existence a priori based only on His nature can be termed an "Ontological Argument". Historically, however, the term is inextricably associated with the famous argument presented in Anselm's Proslogion chapter II, and with the later variant advanced by Descartes in his fifth Meditation and subsequently developed by Leibniz. Some have claimed that Anselm's argument was anticipated in the thought either of various classical philosophers (notably Aristotle, Parmenides, Plato, and Zeno of Cition) or of Augustine, but although there are indeed suggestive passages in their writings, Anselm's explicit "proof" of God's existence based on his Nature does appear to be a genuinely original discovery.

Over the last three years Hume’s use of the term “a priori” has suddenly become very topical. Three discussions, by Stephen Buckle, myself, and Houston Smit, all focusing on Hume’s argument concerning induction in Section IV of the Enquiry, have independently picked up on this question, which seems previously to have gone almost unnoticed.1 That there is an issue here can be seen by examining what Hume says when considering the foundation of our inferences concerning matter of fact; why, for example, we expect a billiard ball to move in a particular way when struck by another: “I shall venture to affirm, as a general proposition, which admits of no exception, that the knowledge of [cause and effect] is not, in any instance, attained by reasonings a priori; but arises entirely from experience … Let an object be presented to a man of ever so strong natural reason and abilities; if that object be entirely new to him, he will not be able, by the most accurate examination of its sensible qualities, to discover any of its causes or effects. … No object ever discovers, by the qualities which appear to the senses, either the causes, which produced it, or the effects, which will arise from it; nor can our reason, unassisted by experience, ever draw any inference concerning real existence and matter of fact.” (E 27, 4.6) In this passage Hume is clearly allowing an object’s “qualities which appear to the senses” as being available to Reason “unassisted by experience”. So what he counts as “experience” seems essentially to involve some memory of prior experience, rather than merely current experience.

The word ‘logic’ as used today is commonly taken to refer to a formal discipline, as indeed it was almost universally from the time of ARISTOTLE until at least the sixteenth century. But the writings of Descartes and his followers (notably Malebranche and the authors of the Port Royal Logic, Arnauld and Nicole) undermined this understanding of the word, preparing the ground for LOCKE to reinterpret it most influentially in his Essay Concerning Human Understanding. Locke adopted from the Cartesians a contempt for the alleged barrenness of Aristotelian syllogistic theory, and aspired to replace it with a discipline focused not on the formal relations of words, but instead on the powers of the human mind and the improvement of our cognitive faculties. It is this kind of informal discipline, therefore, which is most commonly referred to as “logic” by the empiricist authors from Locke to MILL, and indeed their understanding of the logical enterprise persisted until the turn of the twentieth century, when FREGE and RUSSELL firmly reestablished the discipline of formal logic in a new, more powerful, and non-Aristotelian guise.

This paper is the product of an interdisciplinary, interreligious dialogue aiming to outline some of the possibilities and rational limits of supernatural religious belief, in the light of a critique of David Hume’s familiar sceptical arguments -- including a rejection of his famous Maxim on miracles -- combined with a range of striking recent empirical research. The Humean nexus leads us to the formulation of a new ”Common-Core/Diversity Dilemma’, which suggests that the contradictions between different religious belief systems, in conjunction with new understandings of the cognitive forces that shape their common features, persuasively challenge the rationality of most kinds of supernatural belief. In support of this conclusion, we survey empirical research concerning intercessory prayer, religious experience, near-death experience, and various cognitive biases. But we then go on to consider evidence that supernaturalism -- even when rationally unwarranted -- has significant beneficial individual and social effects, despite others that are far less desirable. This prompts the formulation of a ”Normal/Objective Dilemma’, identifying important trade-offs to be found in the choice between our humanly evolved ”normal’ outlook on the world, and one that is more rational and ”objective’. Can we retain the pragmatic benefits of supernatural belief while avoiding irrationality and intergroup conflict? It may well seem that rationality is incompatible with any wilful sacrifice of objectivity. But in a situation of uncertainty, an attractive compromise may be available by moving from the competing factions and mutual contradictions of ”first-order’ supernaturalism to a more abstract and tolerant ”second-order’ view, which itself can be given some distinctive intellectual support through the increasingly popular Fine Tuning Argument. We end by proposing a ”Maxim of the Moon’ to express the undogmatic spirit of this second-order religiosity, providing a cautionary metaphor to counter the pervasive bias endemic to the human condition, and offering a more cooperation- and humility-enhancing understanding of religious diversity in a tense and precarious globalised age.

The ‘New Hume’ interpretation, which sees Hume as a realist about ‘thick’ Causal powers, has been largely motivated by his evident commitment to causal language and causal science. In this, however, it is fundamentally misguided, failing to recognise how Hume exploits his anti-realist conclusions about (upper-case) Causation precisely to support (lower-case) causal science. When critically examined, none of the standard New Humean arguments — familiar from the work of Wright, Craig, Strawson, Buckle, Kail, and others — retains any significant force against the plain evidence of Hume's; texts. But the most devastating objection comes from Hume's own applications of his analysis of causation, to the questions of ‘the immateriality of the soul’ and ‘liberty and necessity’. These show that the New Hume interpretation has misunderstood the entire purpose of his ‘Chief Argument’, and presented him as advocating some of the very positions he is arguing most strongly against

Over the centuries, many different arguments have been used to support the belief in God. These range from the abstruse and theoretical, such as Anselm’s famous Ontological Argument, to the relatively downto-earth and practical, such as Pascal’s Wager; but nearly all of them share a common weakness on which I intend to focus. I shall claim that the theistic arguments typically take for granted that in order to establish the existence of God they have only to establish the existence of a Supreme Being. They thus presuppose that for the office of Lord of the Universe, God as traditionally understood by Christians is the only candidate worth considering, and as a result they give insufficient attention to the nature of the Supreme Being whose existence they supposedly prove.

Is Hume, or is he not, a realist about what Galen Strawson calls “Causation” (with a capital “C”) and Simon Blackburn calls “thick connexions”, that is, necessary connexions between events that go beyond functional relations of regular succession? With this “New Hume” debate now in its third decade, one might feel entitled to wonder whether there is any determinate answer to be had. Both sides have found plenty of Humean quotations to throw at their opponents, passages which taken in isolation might appear to settle the question in their favour. At the same time, both sides have been able to construct plausible accounts of why their opponents’ favoured quotations lack the force that they initially appear to have, and some of these accounts have been not only plausible but philosophically illuminating, unearthing subtle complexities in Hume’s thought which promise – whatever the eventual outcome of the debate – to leave Hume scholarship much richer than had the debate never arisen. This might suggest that the appropriate response is to give up the quest for a definitive answer, to see partial truth on both sides, and to acknowledge that Hume’s thought contains an unresolved tension, with strains both of realism and antirealism about Causation.1 But such a reaction, though natural, would I believe be premature, for two related reasons, concerning respectively the importance to Hume of his theory of causation, and its intimate – but sometimes under-explored – relationships with other aspects of his thought.

I advance what might be thought a paradoxical thesis: that the central topic of Hume’s long discussions “Of the Idea of Necessary Connexion” is not, in fact, the idea of necessary connexion. However it is not as paradoxical as it first appears, for I shall claim that the “idea” whose origin Hume seeks is, in a sense, an idea-type of which the specific idea of necessary connexion is but one instance. Various lines of evidence support this claim, but my main argument will rest on its ability to solve four puzzles in Hume’s text, which are otherwise hard to explain away. These are: (S) the synonymy puzzle, posed by Hume’s apparently reckless assertion that “efficacy”, “agency”, “power”, “force”, “energy”, “necessity”, “connexion”, and “productive quality” are all virtual synonyms; (C) the complexity puzzle, that Hume seems to ignore the possibility that his target idea might be complex rather than simple; (V) the vulgar problem, which arises from Hume’s acknowledgement that the vulgar believe in “chancy” causes, even though he takes the very concept of causation to involve necessity; and (P) the probability problem, of how an allegedly simply idea whose central core involves inexorable necessity could possibly provide a basis for probability. The paper ends by drawing further support from an analysis of Hume’s two sections “Of the idea of necessary connexion”, showing that his use of the various relevant terms makes good sense on the thesis proposed, thus corroborating the arguments presented.

Anselm's Ontological Argument fails, but not for any of the various reasons commonly adduced. In particular, its failure has nothing to do with violating deep Kantian principles by treating ‘exists’ as a predicate or making reference to ‘Meinongian’ entities. Its one fatal flaw, so far from being metaphysically deep, is in fact logically shallow, deriving from a subtle scope ambiguity in Anselm's key phrase. If we avoid this ambiguity, and the indeterminacy of reference to which it gives rise, then his argument is blocked even if his supposed Meinongian extravagances are permitted. Moreover it is blocked in a way which is straightforward and compelling (by contrast with the Kantian objections), and which generalizes easily to other versions of the Ontological Argument. A significant moral follows. Fear of Anselm's argument has been hugely influential in motivating ontological fastidiousness and widespread reluctance to countenance talk of potentially non-existing entities. But if this paper is correct, then the Ontological Argument cannot properly provide any such motivation. Some of the most influential contributions to ontology, from Kant to Russell and beyond, rest on a mistake.