Quine, evidence, and our science

Philosophical Studies (2024) 181:961–976 https://doi.org/10.1007/s11098-024-02116-8 Quine, evidence, and our science Gary Kemp1 Accepted: 27 January 2024 / Published online: 20 March 2024 © The Author(s) 2024 Abstract As is reasonably well-appreciated, Quine struggled with his definition of the allimportant notion of an observation sentence; especially in order to make them bear out his commitment to language’s being a ‘social art’. In an earlier article (Mind 131(523):805–825, 2022), I proposed a certain repair, which here I will explain, justify and articulate further. But it also infects the definition of observation categoricals, and furthermore makes it a secondary matter, a seeming afterthought, that evidence, science and knowledge generally are shared—are joint, social and collaborative products. Without forsaking Quine’s strict naturalism, I try to make the necessary adjustments to Quine’s scheme. Keywords Quine · Knowledge · Evidence · Observation sentences · Publicity · Social dimension 1 Introduction Recent work in epistemology has often focussed on the social dimension of knowledge. Since we learn from others, trust, testimony and transmission would seem to figure essentially in any comprehensive account of knowledge. However, despite being the source of noted sayings such as ‘Language is a social art’, Quine’s epistemology—its author’s being a principal voice of the last generation of epistemologists—has difficulty in satisfying the apparent demands presented by the social demands of knowledge. In this piece, I will make certain adjustments to the fundamentals of Quine’s picture, focussing on his account of evidence—striving not to stray from Quine’s version of naturalism. Since the difficulty, although fundamental, is not widely understood, I will introduce it in some detail in this introduction. According to Quine, the ordinary notion of ‘evidence’ is not quite useable, as-is, in serious epistemology (the reason will be outlined in Section I below). He proposes instead a linguistic surrogate. * Gary Kemp 1 School of Humanities, University of Glasgow, Glasgow G12 8QQ, UK 13 Vol.:(0123456789) 962 G. Kemp Rather than speaking of the ‘evidence’ for an empirical theory, we should speak of the relation of accepted ‘observation categoricals’ to a theory—where observation categoricals are sentences like ‘Whenever it’s snowing, it’s cold’. These are ‘standing sentences’ of the form ‘Whenever o 1, o2’, with o 1 and o 2 being observation sentences (Quine, 1992 p. 1–6; Quine, 1981b p. 27). Observation sentences in turn are a type of ‘occasion’ sentence, which are sentences, by contrast with standing sentences, where one’s disposition to assent to them, as in the example ‘It’s cold!’, may vary without changing one’s on-going theory. What Quine terms the ‘empirical content’ for a theory is given by the totality of its observation categoricals (Quine, 1981b p. 28; Quine, 1992 pp. 16–18). He recommends this, needless to say, not as practical recommendation, but only for making precise philosophical sense of the path from sensory evidence to theory—From Stimulus to Science, to name his last book. Observation sentences themselves are characterized specifically as “intersubjectiv[e]: unlike a report of a feeling [as in ‘I’m hungry’], the sentence must command the same verdict from all linguistically competent witnesses of the occasion” (p. 3). They are characterized still further in terms of their”stimulus meaning” (WO §8)—as sentences that are “associated affirmatively with some range of one’s stimulations and negatively with some range” (Quine, 1992 p. 3). The apparent difficulty with this picture is that you and I may agree in our verdicts for a given utterance of an observation sentence, but what I mean and what you mean by the sentence, in the only sense of ‘meaning’ strictly speaking available to Quine, is not the same. In fact it never is the same. For ‘stimulations’, which figure in the characterization of observation sentences via stimulus meaning, are understood as triggered sensory receptors, and “two persons do not share the same receptors…[t]hey do not even have exactly homologous receptors”(Quine, 1981c pp. 50–51). After Word and Object (1960) Quine acknowledged this difficulty—of the idiosyncrasy of the stimulus meaning of observation sentences—and took steps to circumvent it. In his last works of the 1990s he offered an evolutionary explanation, or at least a schema for one, of the intersubjective agreement of verdicts of observation sentences in terms of ‘pre-established harmony’. I will describe this further below. A further ramification—not discussed by Quine—is that the idiosyncrasy of stimulus meaning of observation sentences appears to infect the empirical content of an empirical theory, its collection of observation categoricals. An observation categorical like ‘When it’s snowing, it’s cold’ comprises observation sentences which have different stimulus meanings for you and for me, as I will explain. I will propose an alternative, a scheme that: (1) Makes it straightforward that the content of observation sentences and that of observation categoricals are intersubjective, and does not vary across different speakers, at least not substantially. (2) Restores the concept of ‘evidence’: makes it straightforward to speak of ‘our’ evidence as well as the evidence of this or that individual, construing knowledge and theories as social phenomena, not as the possession of individuals. 13 Quine, evidence, and our science 963 (3) Is consistent with Quinean basic tenets, and, in particular, serves the purposes of Quinean Naturalism and Naturalized Epistemology. In an earlier piece (Kemp 2022) I have made part of the case for (1). I will explain this briefly below. I shall then propose an extension of the point to observation categoricals, and will make the case for (2). The resulting picture assigns a more robust objectivity to observation, and it allows us to speak without qualification of the evidence had by others, to make use of it, and to construe theories as straightforwardly public, collaborative, and as jointly held. (3) is a more acute matter than it might first appear, owing to the qualification ‘Quinean’. I will explain some of the main points in this respect, especially the importance for Quine of not simply acquiescing in Davidson’s recommendation of a distal conception of observation.1 2 Observation, evidence and pre‑established harmony 1. The relation of evidence to theory, and in particular of observation to theory, is of the first importance to any empiricist, and certainly so to Quine, who wrote such things as that “[T]he stimulation of his sensory receptors is all the evidence anybody has had to go on, ultimately, in arriving at his picture of the world” (1969, pp. 75–6). But Quine finds the notion of evidence, and indeed that of an observation, to be “awkward to analyse”—awkward on account of their naturally invoking object (...truncated)