Brian Ellis advances a robust species of realism he calls Physical Realism. Physical Realism includes an ontology comprising three kinds of universal and three kinds of particular: a six‐category ontology. After comparing Physical Realism to a modest two‐category ontology inspired by Locke, I mention two apparent difficulties a proponent of a six‐category ontology might address.1.

To be a realist about modality, need one claim that more exists than just the various objects and properties that populate the world—e.g. worlds other than the actual one, or maximal consistent sets of propositions? Or does the existence of objects and properties by itself involve the obtaining of necessities (and possibilities) in re? The latter position is now unpopular but not unfamiliar. Aristotle held that objects have essences, and hence necessarily have certain properties. Recently it has been argued that (...) the identity of any property is tied to the natural laws in which it figures, which entails that the occurrence of properties involves the obtaining of nomological necessities ([24], pp. 206-33 and 234-60; [23]; cf. [25] and [6]). Somewhat less recently, Wittgenstein ([28], p. 168) worried that the reality of at least some properties—precise shades of colors being a prime example—involved the obtaining in re of certain impossibilities. This paper argues that Wittgenstein’s worries were right, and not just concerning some properties, but all properties whatever. That there are objects and properties in the world at all, then, amounts to there obtaining modal states of affairs. This argument supplements, rather than replaces, the others. The position on property incompatibility advanced here actually helps defend Aristotelian essentialism against epistemological objections, or so I have argued ([15]). And while this paper’s position on property incompatibility diverges from the idea that a property’s nomic profile is essential to it—more on this in the next section—it is at least compatible with the thought that the necessity involved in the laws of nature enters into ontology at the ground level. (shrink)

The object of this paper is to show why recent research in the psychology of deductive and probabilistic reasoning does not have.

The goal of this dissertation is to contribute to the epistemology of science by addressing a set of related questions arising from current discussions in the philosophy and science of climate change: (1) Given the imperfection of computer models, how do they provide information about large and complex target systems? (2) What is the relationship between consilient reasoning and robust evidential support in the production of scientific knowledge? (3) Does taking the mean of a set of model outputs provide epistemic (...) advantages over using the output of a single ‘best model’? Synthesizing research in philosophy and science, the thesis analyzes connections among consilient inductions, robustness analysis, and the aggregation of various sources of evidence, including computer simulations, by investigating case studies of climate change that exemplify the strength of consilient reasoning and the security of robust evidential support. It also explains the rationale and epistemic conditions for improving estimates by averaging multiple estimates, comparing a simple case of averaging estimates to practices in multi-model ensemble studies. I argue: (A) the concepts of consilience and robustness account for the strength and security of inferences that rely on imperfect computer modelling methods, (B) consilient reasoning is conducive to attaining robust evidential support, and (C) an analogy can explain why averaging the outputs of multiple models can improve estimates of a target system, given that conditions of model independence, skill and unequal weighting are taken into account. (shrink)