Transitivity of visual sameness

The way in which vision represents objects as being the same despite movement and qualitative changes has been extensively investigated in contemporary psychology. However, the formal properties of the visual sameness relation are still unclear, for example, whether it is an identity-like, equivalence relation. The paper concerns one aspect of this problem: the transitivity of visual sameness. Results obtained by using different experimental paradigms are analysed, in particular studies using streaming/bouncing stimuli, multiple object tracking experiments and investigations concerning object-specific preview benefit, and it is argued that the transitive interpretation of visual sameness is the most plausible given the current stage of knowledge. What is more, it is claimed that the way in which visual sameness is represented suggests that in some cases it should be characterized as a “primitive sameness”, similarly as in philosophical theories postulating “thisness”

The nonclassical mereology of olfactory experiences

While there is a growing philosophical interest in analysing olfactory experiences, the mereological structure of odours considered in respect of how they are perceptually experienced has not yet been extensively investigated. The paper argues that odours are perceptually experienced as having a mereological structure, but this structure is significantly different from the spatial mereological structure of visually experienced objects. Most importantly, in the case of the olfactory part-structure, the classical weak supplementation principle is not satisfied. This thesis is justified by referring to empirical results in olfactory science concerning the human ability to identify components in complex olfactory stimuli. Further, it is shown how differences between olfactory and visual mereologies may arise from the way in which these modalities represent space

On the consequences of a Mihlin-H\"ormander functional calculus: maximal and square function estimates

We prove that the existence of a Mihlin-H\"ormander functional calculus for an operator $L$ implies the boundedness on $L^p$ of both the maximal operators and the continuous square functions build on spectral multipliers of $L.$ The considered multiplier functions are finitely smooth and satisfy an integral condition at infinity. In particular multipliers of compact support are admitted

A presentation for the mapping class group of a non-orientable surface from the action on the complex of curves

We study the action of the mapping class group M(F) on the complex of curves of a non-orientable surface F. We obtain, by using a result of K. S. Brown, a presentation for M(F) defined in terms of the mapping class groups of the complementary surfaces of collections of curves, provided that F is not sporadic, i.e. the complex of curves of F is simply connected. We also compute a finite presentation for the mapping class group of each sporadic surface.Comment: 45 pages, accepted for publication in Osaka J. Mat

Islam, the Arabs and Umayyad Rulers according to Theophanes the Confessor’s Chronography

Translated by Konrad FigatAs the Chronography of Theophanes the Confessor includes a lot of information about the foreign states and tribes which were connected with the Byzantine Empire. It is legitimate, in the Author’s view, to analyse the account concerning Islam and the Arabs by this Byzantine author. Theophanes possessed detailed knowledge of the Arabs, Islam and Umayyad caliphs. He used, although presumably indirectly, some Muslim sources in his work. The argument which strongly proves this hypothesis is his precise description of inner clashes between the members of the ruling house, as well as of Arab civil wars. The article discusses how Theophanes (and presumably his sources) depicted not only the Arabs as an entity, but also the prophet Muhammad and some of the Umayyad caliphs (Muawiya, Walid I, Umar II, Hisham, Marwan II)

Perceptual Kinds as Supervening Sortals

It seems intuitive that in situations of perceptual recognition additional properties are represented. While much has been written about the significance of such properties for perceptual phenomenology, it is still unclear (a) what is the relation between recognition-based properties and lower-level perceptual properties, and (b) whether it is justified to classify them as kind-properties. Relying on results in cognitive psychology, I argue that recognition-based properties (I) are irreducible, high-level properties, (II) are kind properties by virtue of being sortal properties, but (III) they supervene on lower-level properties and so are unlikely to be natural kind properties