Heuristics, Concepts, and Cognitive Architecture: Toward Understanding How The Mind Works

Heuristics are often invoked in the philosophical, psychological, and cognitive science literatures to describe or explain methodological techniques or shortcut mental operations that help in inference, decision-making, and problem-solving. Yet there has been surprisingly little philosophical work done on the nature of heuristics and heuristic reasoning, and a close inspection of the way(s) in which heuristic is used throughout the literature reveals a vagueness and uncertainty with respect to what heuristics are and their role in cognition. This dissertation seeks to remedy this situation by motivating philosophical inquiry into heuristics and heuristic reasoning, and then advancing a theory of how heuristics operate in cognition. I develop a positive working characterization of heuristics that is coherent and robust enough to account for a broad range of phenomena in reasoning and inference, and makes sense of empirical data in a systematic way. I then illustrate the work this characterization does by considering the sorts of problems that many philosophers believe heuristics solve, namely those resulting from the so-called frame problem. Considering the frame problem motivates the need to gain a better understanding of how heuristics work and the cognitive structures over which they operate. I develop a general theory of cognition which I argue underwrites the heuristic operations that concern this dissertation. I argue that heuristics operate over highly organized systems of knowledge, and I offer a cognitive architecture to accommodate this view. I then provide an account of the systems of knowledge that heuristics are supposed to operate over, in which I suggest that such systems of knowledge are concepts. The upshot, then, is that heuristics operate over concepts. I argue, however, that heuristics do not operate over conceptual content, but over metainformational relations between activated and primed concepts and their contents. Finally, to show that my thesis is empirically adequate, I consider empirical evidence on heuristic reasoning and argue that my account of heuristics explains the data

Deixis (demonstratives and adverbials) in Hausa.

This thesis investigates deixis in Hausa. Specifically, it examines the deictic interpretation of Hausa demonstratives, adverbs and certain deictic particles within a systematic paradigm of referential interpretation. I show that the participant-based approach to Hausa deictic adverbials, first proposed by Jaggar and Buba (1994), can be extended to cover other (related) deictic elements. In that work, we demonstrated how the tripartite system of spatial, anaphoric and symbolic usage interacts with the speaker-proximal, speaker-distal and speaker/addressee-distal distinctions encoded by NAN- and CAN-adverbials. In this thesis, the same model is extended to explain the functional distribution of the related demonstratives WANNAN and WANCAN. Chapter 1 provides a general introduction to the notion of deixis, covering its definition and various manifestations in the referential subsystems of demonstratives, adverbs (and personal pronouns). Chapter 2 addresses the speaker-proximal demonstrative and adverbial deictics (e.g. nan 'here' [near me the speaker], wannan + NP, NP-n/r- nan/nan 'this NP [near me the speaker]'). Chapter 3 is concerned with the basically addressee-proximal deictics (e.g. nan 'there [near you the addressee]', wannan / wannan + NP, NP-n/r-nan 'that NP [near you the addressee]'). In Chapter 4, I look at the speaker/addressee-distal forms (e.g. can 'there [distant from speaker and addressee]', wancan + NP, NP-n/r-can/can 'that NP [distant from speaker and addressee]'), and their remote-distal counterparts (e.g. can 'over there [remote from speaker and addressee]', wancan / wancan -i- NP, NP-n/r-can 'that NP [remote from speaker and addressee]'). The functional distribution of the pre-head and post-head demonstratives is described and explained in terms of the semantic-pragmatic notion of presuppositionality. The core claims are summarised in Chapter 5, where I briefly address the implications of the findings for the Hausa system of deixis, and for cross-linguistic deictic theory in general