“Ethics With Ontology” both alludes to and contrasts with Hilary Putnam’s book Ethics Without Ontology (2004). In this book, Putnam proposes that there can be moral objectivity without objects, or moral truth without any description of a moral realm. Since then, many others (for instance, T. Scanlon, R. Dworkin, C. Korsgaard, and D. Parfit) have claimed that the view that there are moral truths has no ontological implications. They opt instead for a metaethical cognitivism without moral realism. On the other hand, one of the most striking developments in the metaethical debate of the past 15 years has been the renewal of non-naturalist moral realism—the view which (at least in its so-called “robust” versions) presents the strongest ontological and metaphysical commitments, namely commitments to the existence of non-natural properties and facts.

The papers collected in this special issue both illuminate and take various positions on the topic of the ontological and metaphysical commitments of non-naturalist moral realism, as well as on some of the various puzzles related to it. One group of papers focuses on the contraposition between ontologically robust and ontologically light views. W. Fitzpatrick’s “Ontology for an uncompromising ethical realism”, B. Niederbacher’s “An ontological sketch for robust non-reductive realists” and G. Gasser’s “Normative objectivity without ontological commitments?” all discuss metaethical cognitivism without realism, approaching it from a robustly realist point of view. A common target of their criticisms is Parfit’s highly debated “non-metaphysical cognitivism”, according to which there are true, irreducibly moral claims that have “no positive ontological implications” (Parfit 2011, p. 486). Both Gasser and Niederbacher argue against the idea of a non-ontological sense of existence with reference to moral entities, and rely on E. J. Lowe’s four-category ontology to show how these moral entities can be thought of as included in the “furniture of the world” (Mackie 1977, p. 16). Fitzpatrick, in addition to discussing Parfit’s non-metaphysical cognitivism, also examines Scanlon’s claim that the ontological question about the existence of a particular kind of entity is internal to the specific domain of discourse in which that particular kind of entity is spoken of. Against such a Carnapian view, according to which there are “no bases for standards of existence beyond those of these particular domains” (Scanlon 2014, p. 24), Fitzpatrick argues for the inescapability of a domain-general ontology that recognises the existence of moral and normative properties that are not reducible to the properties investigated by the natural sciences. However, while Fitzpatrick, in prior work, conceived this “dual aspect view” as implying a “non-naturalistic metaphysics of ethical facts and properties” (Fitzpatrick 2008, p. 161), here he prefers to appeal to Russell’s Neutral Monism and to characterize his position as a “Non-Scientistic Naturalism”, according to which the natural realm comprises more than science reveals. J. Suikkanen’s “Contractualism as restricted constructivism”, by contrast, is sympathetic to Scanlon’s ontologically lightweight metaethical position. He discusses Scanlon’s idea of regarding the second-order ontological question about the existence of non-natural moral properties and facts as internal to the first-order domain of morality. More specifically, Suikkanen begins with a rejection of the correspondence notion of truth, favouring instead C. Wright’s epistemic notion of superassertibility, and argues for a new, restricted contractualist form of constructivism. According to this view, a normative theory such as Scanlon’s contractualism enables us to detect which reasons are relevant and non-constructed; the information about these reasons makes normative claims superassertible, i.e., only minimally true. Within this framework, normative facts about rightness and wrongness are not mind-independent facts that exist “out there” and make normative sentences true, but rather constructed facts: “The property of wrongness is a projection from the minimally true statements about wrongness”. A similarly lightweight form of non-naturalism is advanced, though only indirectly, in F. Orsi’s “Ethical non-naturalism and the guise of the good”. According to the guise-of-the-good theory of desire, everything an agent desires is desired under the “guise of the good”, that is to say, the agent thinks that it is good. Orsi’s argument is hypothetical: if the guise-of-the-good theory of desire were correct, then the metaethical view that best coheres with this theory would be a metaphysically minimal form of non-naturalism. Next comes G. Mancuso’s “Enoch’s ‘Taking-morality-seriously thought’ unpacked and at work in the argument from impartiality”. The author analyses one of Enoch’s arguments for robustly non-naturalist moral realism, makes explicit what she thinks are its underlying assumptions, and argues that Enoch’s attempt to use the “taking-morality-seriously thought” as a basis of a theoretical inquiry into the nature of morality does not work. In his “Impartiality and Realism: Reply to Mancuso”, Enoch responds to Mancuso’s criticisms, defending the idea of arguing in favour of robustly non-naturalist moral realism by relying on the morally objectionable implications of competing metaethical views, and discussing the methodological criteria according to which rival metaethical explanations should be evaluated.

An ontology of moral properties gives rise to metaphysical questions such as: Are moral properties different in nature from the properties that natural sciences investigate, thus deserving the label “non-natural”? How should their relationship with natural properties be explained? If the relationship is a kind of supervenience, then how are we to understand it? And, given their non-naturalness, how can moral properties do any significant explanatory work? These are the issues on which the second group of papers focuses. G. Oddie’s “Non-naturalist moral realism, autonomy and entanglement” deals with the relationship between the moral (or more generally the normative) on the one hand, and the natural on the other. Against the idea that these two spheres are autonomous (an idea supported by the well-known Humean observation that an ought should not be derived from an is, in conjunction with G. E. Moore’s thesis about the indefinability of good), Oddie argues for the existence of a deep entanglement between the normative and the natural. This entanglement—he claims—is neither as shallow as logical arguments like A. Prior’s (1960) might indicate, nor as deep and pervasive as the naturalist moral realist claims. However, the entanglement is deep enough to avoid, for instance, the problem of explaining how we can have epistemic access to moral properties. T. McPherson’s paper, “Explaining practical normativity”, focuses on the charge that naturalist moral realists cannot explain the distinctive kind of normativity in play in the practical domain. McPherson asks whether non-naturalist moral realists really are in a better position to discharge this explanatory task and thus to metaphysically vindicate practical normativity. His response is negative, because of the “mysterianism” about normativity that, in his opinion, characterizes non-naturalist moral realism, by which he means the view that normativity is “something we must simply accept as brute and inexplicable feature of reality”. In sharp contrast to McPherson’s charge of “mysterianism” against non-naturalism, A. Corradini’s “Essentialism and nonnaturalist normative supervenience” maintains that the normative is explainable within the framework of essentialist grounding. This accounts both for the metaphysical necessity of the relationship of normative supervenience, and for the semantic autonomy of the normative towards the natural. Moreover, Corradini shows that the supervenience relation between the natural and the normative is immediate, that is, it does not rely on intermediate hybrid properties, as S. Leary (2017) argues. Leary’s notion of a hybrid property is also critically analysed by T. Toppinen’s “Essentially grounded non-naturalism and normative supervenience”. Against Leary’s non-naturalist-friendly proposal to explain normative supervenience within an essentialist metaphysical framework by means of hybrid properties, Toppinen argues that there are no properties “whose essences determine both naturalistic sufficient conditions for their instantiation and sufficient conditions for the instantiation of other sui generis normative properties”.