This thesis offers a defence of naive realism. As I understand it, naive realism involves a claim about the structure of perception, and about the nature of perceptual experience, that is, the sensory experience that one enjoys when perceiving something. It claims that perception is psychologically direct, in that perceptual experience, in its very nature, suffices to put one in contact with normal, mind-independent objects. And it understands this nature in terms of it being presentational of these objects. After explaining the core commitments of naive realism and presenting the salient alternative views of the nature of perceptual experience and perception, I go on to consider motivations for why it is a position that is worth defending. I discuss epistemological, metaphysical and phenomenological reasons for why naive realism should be the place where we begin our theorising about perception, and why we should defend it as strongly as we can. I then present the two main challenges to the naive realist view, the arguments from illusion and hallucination. The possibility of these two kinds of sensory experience is held to make the naive realist view of the nature of perceptual experience untenable. I present a modified form of adverbialism as the best way for the naive realist to understand the nature of perceptual experience if they want to successfully accommodate the possibility of illusory experience. On this approach, perceptual experience is the sensing of the object of perception by a subject. Next I consider the disjunctive response to the challenge that hallucination presents to the naive realist, according to which we should conceive of perceptual and hallucinatory experience as having fundamentally different natures. I argue that such a disjunctivism needs to take an extreme form in which the only positive nature to hallucinatory experience is its being subjectively indiscriminable from perceptual experience. This position is rejected on the grounds that it maintains an implausible view about the nature of sensory experience. Finally, I consider an alternative way in which the naive realist can deal with hallucination. This is to claim that perceptual and hallucinatory experience can share the same nature, while at the same time perceptual experience can be understood as presentational of the objects of perception. This strategy will require the naive realist to adopt a stance about the metaphysical nature of the entities to which one can be related in experience.

Ethical Realism and the Biosciences is an investigation into whether the ethical theory of realism can be justified on a naturalistic basis in light of modern biological discoveries. The author claims that ethical realism is the case for a core of human ethical precepts that are shared across all human cultures - the prohibitions on lying, stealing, cheating, harming, and murdering. This is based on the existence of moral facts that are motivated by moral emotions bequeathed to us by evolution, but justified through the use of reasoning about what we have reason to do to make the life of the community go well. Naturalistic ethical realism is buttressed by the fact that evolution not only selected for the moral emotions, but itself 'tracks' the flourishing of species. Sociobiology, ethology, neurology, biochemistry, and anthropology are all utilized in the canvas of how we actually make ethical decisions. T~is leads to a new theory of moral emotions and their effect in ethical action. An argument is presented for a culture-independent and person-independent, but species-dependent ethical realism. It is postulated t6 be built of moral modules that offer an explanation for moral disagreement around a realist core. This study contends that a defence of naturalistic ethical realism and the evolutionary psychology on which it is built makes four contributions to a Christian theology of sin. It defines a relationship between wrongdoing and sin, and posits that a naturalistic justification of wrong-doing lends apologetic heft to Christian doctrine. It gives support to the notion that we are responsible, and combats the threat of genetic determinism. The theory of emotional interaction in ethical decision-making on which it is built supports the importance of training in virtue. Finally, it provides an alternative basis for an etiological myth of original sin.

In this dissertation, I examine a view called 'Epistemic Structural Realism', which holds that we can, at best, have knowledge of the structure of the physical world. Put crudely, we can know physical objects only to the extent that they are nodes in a structure. In the spirit of Occam's razor, I argue that, given certain minimal assumptions, epistemic structural realism provides a viable and reasonable scientific realist position that is less vulnerable to anti-realist arguments than any of its rivals. The first chapter presents an overview of the scientific realism debate, concentrating on the epistemological dimension. The second chapter tracks the development of structural realism, differentiates between several versions, and outlines the objections that have been raised against it. The third chapter provides answers to a large subset of these objections, namely those launched by Stathis Psillos, who spearheads the critique of epistemic structural realism. The fourth chapter offers an attempted solution to M.H.A. Newman's objection that the epistemic structural realist view, if true, trivialises scientific knowledge. The fifth chapter presents a historical case study of the caloric theory of heat. I utilise the study to answer the pessimistic meta-induction argument. The sixth chapter addresses the argument from the underdetermination of theory by evidence. I argue that epistemic structural realism can potentially restrict the impact of the argument by imposing structural constraints on the set of all possible theories compatible with the evidence. The seventh and final chapter outlines briefly some promising avenues for future research.

This thesis has two philosophical positions as its targets. The first is 'scientific realism' of the form defended by Boyd, (the early) Putnam, and most recently Psillos. The second is empiricism in the vein of Mill, Mach, Ayer, Carnap, and Van Fraassen. My objections to both have a rather Popperian flavour. For I argue that 'confirmation' is a misnomer, that so-called 'ampliative inferences' are heuristics at best, and that naturalism and subjectivism are regressive doctrines. At the heart of genuine realism, I argue, is a stance on the issues of perception and conception. In particular, I hold that to be a realist is to reject the notion that there are representations which have some sort of epistemic priority. And along related lines, I maintain that the closely aligned doctrine of physicalism cannot simply be presupposed. What this amounts to is that the search for some sort of 'solid foundation' for knowledge' is a futile enterprise. Such a foundation would be unimportant, even if there were to be one, and we ought to be free to critically examine any claim we like. So rather than sapere aude, I would have 'dare to err', and place an intersubjective emphasis on inquiry. And this goes for metaphysics, logic, and mathematics, as well as for natural science. Yet I also advocate the view that we ought to be optimistic about our ability to find the truth, ceteris paribus. And to this end, I argue that we should accept that our faculty of conception is sufficient to allow us to connect with the possibilities of being, whereas our faculty of sense is sufficient to allow us to connect with that which is actual; this, given considerable critical struggle on our parts, both individually and collectively. I urge that it is methodologically advisable to behave as if this is so, if we are not to асһieve only the self-paralysis of the Pyrrhonist. In a nutshell, destructive realism says that natural science progresses by ruling out possibilities, in particular by ruling out possible worlds as candidates for the actual world, but that this is a two-stage process, involving both an a priori (metaphysical) and an a posteriori (observational) component. The aim of natural science is to eliminate false theories. Its aspiration is truth.

This thesis sets out to challenge the assumption widely held among IR scholars that Scientific Realism (SR) is the definite and final interpretation of realism. The introduction of SR into IR as the latter’s proper meta-theory has been the incentive for very intense debates about both meta-theoretical and theoretical IR issues. I argue that IR has uncritically adopted the strongest version of SR. This can be seen by comparing the different versions of SR and their anti-realist alternatives - as these have developed in the Philosophy of Science literature - to the version of SR which was introduced into IR. It is Critical Realism (CR), however, a version of SR that originated with Roy Bhaskar, which has dominated the SR debate in IR. This development has had negative consequences with respect to the quality of the argumentation about realism in IR. This notwithstanding, a positive implication of this situation is that IR scholars who belong in various traditions of thought have criticized SR from different theoretical angles and thus shed light on many of its shortcomings. I elaborate on the comments that have been made on meta-theoretical as well as theoretical issues and come up with my own conclusions about SR and CR. In this framework, I also deal with two special issues which have arisen from this debate’s problematique: the question about whether reasons can be causes, which lies in the foundations of Wendt’s ‘constitutive explanation’, and the challenge of ‘meta-theoretical hypochondria’, according to which the extensive concern with meta-theory takes place at the expense of theorizing real-world political problems. Last, I show, by a way of a novel contribution, that Wendt’s latest undertaking, of a ‘quantum social science’, although compatible with SR, suffers inconsistencies and misunderstandings in terms of its methodology, metaphysics, use of quantum mechanics, and application to IR. This thesis is an interdisciplinary study, which draws upon the Philosophy of Science, IR and Physics (namely Quantum Mechanics), in order to scrutinize the use of SR and CR into IR along with its implications for both IR metatheory and IR theory.

This work is intended to ascertain whether Putnam’s internal realism is actually a realist doctrine. Putnam has opposed internal realism, which maintains that truth is an epistemic notion (specifically, idealised rational acceptability), to metaphysical realism, which holds that truth is a non-epistemic notion (in particular, a correspondence relationship between sentences and extra-linguistic facts). Putnam has argued that, even if metaphysical realism is untenable, realism is still defensible, for internal realism is a form of realism. In my work, I leave aside the question of the correctness of Putnam’s arguments against metaphysical realism and I directly focus upon internal realism. I first present this position and I set out its realist characteristics: Putnam’s position can be characterised as one that originated in an attempt to develop Dummett’s anti-realist notion of truth in a realist direction. I show that this effort is in part successful. Next, I raise objections against internal realism and I show that, despite its merits, Putnam’s position is not a form of realism. This is so mainly because internal realism may collapse into relativism, which – I argue – is not realism, and because the internal realist cannot explain how the world, which is causally independent of our minds, makes statements true or false. Since Putnam’s probably constitutes the best possible attempt to produce an epistemic view of truth compatible with realism, I conclude that truth conceived as an epistemic notion is incompatible with realism. I finally suggest that realism can be restored if Putnam’s arguments against metaphysical realism can be shown to be incorrect, so that a non-epistemic notion of truth can be rehabilitated.