A perceptual account of definitions

The traditional definition per genus et differentiam is argued to be cognitively grounded in perception and in order to avoid needless argument, definitions are stipulated to assert boundaries. An analysis of the notion of perspective shows that a boundary is a composite of two distinctions: similarity that includes and difference that excludes. The concept is applied to the type-token distinction and percepts are shown to be the result of a comparison between a token as representing some phenomenon and a type as representing the kind of object the phenomenon might be. The Principle of Connection is proposed as the mental architecture that gives rise to percepts. The value of a percept is shown to be one of Identical, Similar, Different or Contrary and its perceptual aspects represent the cognitive schema of Essence, Quality, Quantity and Relation. The two notions of similarity and difference are claimed to constitute the necessary and sufficient conditions for definitions. Accordingly, the qualitative elements of a definition signify the genus as representing the similarity of the defined entity in terms of others of its kind and the quantitative elements signify the differentia as representing the difference it has from everything else. Paying proper attention to both qualitative and quantitative aspects will enable formulation of definitions that are ‘good’. This paper is based on my master’s thesis at Monash University (2003). I thank Keith Allan for commenting on an earlier draft—any remaining infelicities are mine only.     

Scanlon’s modal metaphysics

In Being Realistic About Reasons (Oxford University Press, 2014) T. M. Scanlon argues that particular fact about reasons are explained by contingent non-normative facts together with pure normative principles. A question then arises about the modal status of these pure principles. Scanlon maintains that they are necessary in a sense, and suggests that they are ‘metaphysically’ necessary. I argue that the best view for Scanlon to take, given his other commitments, is that these pure normative principles are metaphysically contingent in some cases and necessary only in a weaker sense.     

Do you remember where sounds,pictures and words came from? The role of the stimulus format in object location memory

Contrasting results in visual and auditory spatial memory stimulate the debate over the role of sensory modality and attention in identity-to-location binding. We investigated the role of sensory modality in the incidental/deliberate encoding of the location of a sequence of items. In 4 separated blocks, 88 participants memorised sequences of environmental sounds, spoken words, pictures and written words, respectively. After memorisation, participants were asked to recognise old from new items in a new sequence of stimuli. They were also asked to indicate from which side of the screen (visual stimuli) or headphone channel (sounds) the old stimuli were presented in encoding. In the first block, participants were not aware of the spatial requirement while, in blocks 2, 3 and 4 they knew that their memory for item location was going to be tested. Results show significantly lower accuracy of object location memory for the auditory stimuli (environmental sounds and spoken words) than for images (pictures and written words). Awareness of spatial requirement did not influence localisation accuracy. We conclude that: (a) object location memory is more effective for visual objects; (b) object location is implicitly associated with item identity during encoding and (c) visual supremacy in spatial memory does not depend on the automaticity of object location binding.