Frauke Hildebrandt

Perner and Roessler Causing human action: new perspectives on the causal theory of action, MIT Press, Cambridge, MA, pp 199–228, 2010) hold that children who do not yet have an understanding of subjective perspectives, i.e., mental states, explain actions by appealing to objective facts. In this paper, we criticize this view. We argue that in order to understand objective facts, subjects need to understand perspectives. By analysing basic fact-expressing assertions, we show that subjects cannot refer to facts if they do not understand two types of perspectivity, namely, spatial and doxastic perspectivity. To avoid conceptual confusion regarding different ways of referring to facts, we distinguish between reference to facts de re and de dicto.

Among the philosophical accounts of reference, Quine’s The Roots of Reference stands out in offering an integrated account of the acquisition of linguistic reference and object individuation. Based on a non-referential ability to distinguish bodies, the acquisition of sortals and quantification are crucial steps in learning to refer to objects. In this article, we critically re-assess Quine’s account of reference. Our critique will proceed in three steps with the aim of showing that Quine effectively presupposes what he sets out to explain, namely, reference to objects. We are going to argue that sortals do not individuate, that bodies are already objects, and that the acquisition of variables presupposes a notion of identity. The result is diagnostic of a central desideratum for any theory of reference: an explanation of spatiotemporal object individuation.

The current understanding of cognitive development rests on the premise that infants can individuate objects early on. However, the so-called object-first account faces severe difficulties explaining extant empirical findings in object individuation tasks while alternative, more parsimonious explanations are available. In this paper, we assume that children start as feature-thinkers without being able to individuate objects and show how this ability can be learned by thinkers who do not already implicitly possess the notion of an object. Based on Tugendhat's ideas on the relation between singular terms and object reference, we argue that spatial indexicals comprise the fundamental means of object individuation and describe how feature thinkers might acquire the complex substitutional system of spatial indexicals. In closing, two accounts of object cognition that do not rely on symbolic capacities, namely Pylyshyn's FINST indexes and Burge's perceptual objectivity, are critically discussed.

Numerical magnitude information is assumed to be spatially represented in the form of a mental number line defined with respect to a body-centred, egocentric frame of reference. In this context, spatial language skills such as mastery of verbal descriptions of spatial position have been proposed to be relevant for grasping spatial relations between numerical magnitudes on the mental number line. We examined 4- to 5-year-old’s spatial language skills in tasks that allow responses in egocentric and allocentric frames of reference, as well as their relative understanding of numerical magnitude. In addition, we evaluated influences of children’s absolute understanding of numerical magnitude assessed by their number word comprehension and of their knowledge on numerical sequences. Results indicated that when considering responses that corresponded to the egocentric perspective, children’s spatial language was associated significantly with their relative numerical magnitude understanding, even after controlling for covariates, such as children’s SES, mental rotation skills, and also absolute magnitude understanding or knowledge on numerical sequences. This suggests that the use of egocentric reference frames in spatial language may facilitate spatial representation of numbers along a mental number line and thus seem important for preschoolers’ relative understanding of numerical magnitude.

While research on object individuation assumes that even very young children are able to perceive objects as particulars, we argue that the results of relevant studies can be explained in terms of feature discrimination. We propose that children start out navigating the world with a feature‐based ontology and only later become able to individuate objects spatiotemporally. Furthermore, object individuation is a cognitively demanding achievement resting on a uniquely human form of enculturation, namely the acquisition of deictic demonstratives. We conclude by outlining empirical expectations for operationalizations of our proposal.

We argue that objectivity is acquired by learning to refer to particular situations, that is, by developing episodicity. This contrasts with the widespread idea that genericity is crucial in developing humans’ ability to conceive of an objective world. According to the collective intentionality account, objectivity is acquired by contrasting one’s particular perspective in the “here and now” with a generic group perspective on how things are generally. However, this line of argument rests on confusing two independent notions of genericity: social and worldly genericity. Holding these two notions apart shows that there is no coherent developmental route from episodicity to objectivity via genericity. In effect, the collective intentionality account presupposes objectivity. Alternatively, episodicity may develop by enculturation into the common practice of spatial-indexical use. This ability establishes an initial, socially shared spatiotemporal reference system comprising the basis for objectivity.

The ability to refer to objects – singular reference – is arguably the decisive innovation on the way to human propositional cognition. This article argues that object individuation requires singular reference because basic singular terms, namely spatial indexicals, provide a symbolic frame of reference for object individuation. The authors suggest that singular reference is intrinsically connected to essential characteristics of propositionality: among other things, it guarantees the situation-independence of meaning, allows for the distinction between truth and falsehood, and enables us to think about possibilities. The authors sketch how singular reference gives rise to the development of predication, the powerful logical tool of quantification, and forms the basis for differentiating between belief and desire.

Human thought can be characterised as being situated in the ‘space of reasons’. That is to say that human thought is guided by the norms of theoretical and practical rationality which, in turn, enable autonomous thinking. But how do children learn to navigate the space of reasons? Building on the work of Tugendhat and Bakhurst, among others, we argue, first, that this process involves the acquisition of propositional thought and that it is an essentially social one in which both children and adults take an active role. Second, and more specifically, by drawing on Brandom's theory of meaning, we provide a philosophical analysis of empirical findings with respect to the efficacy of ‘Sustained Shared Thinking’ (SST) in early educational settings. We argue that the efficacy of SST is based on its emphasising, modelling and practising those elements of communication that are essential for gaining proficiency in ‘playing the game of giving and asking for reasons’, namely drawing inferences between propositions and concepts and providing justifications for one's assertions. This is achieved by making explicit the inferential relationships between concepts and propositions and by the use of modal and doxastic markers that function as an invitation to a joint search for reasons.