The paper is an exercise in descriptive ontology, with specific applications to problems in the geographical sphere. It presents a general typology of spatial boundaries, based in particular on an opposition between bona fide or physical boundaries on the one hand, and fiat or human-demarcation-induced boundaries on the other. Cross-cutting this opposition are further oppositions in the realm of boundaries, for example between: crisp and indeterminate, complete and incomplete, enduring and transient, symmetrical and asymmetrical. The resulting typology generates a corresponding (...) categorization of the different sorts of objects which (complete) boundaries determine or demarcate. The theory is applied first of all in the areas of geography and of administrative and property law. Indications are then given as to how the typology may be applied also in other fields where physical and fiat boundaries are at work, including the field of cognitive linguistics and the related field of the ontology of truth. (shrink)

We only need to think for a moment about surfaces and other interfaces to realise their enormous importance in everydaylife. There are numerous branches of physics, chemistry, biology, and materials science concerned wholly or largely with surfaces, and one sometimes comes across the expression ‘surface science’ Among the natural phenomena connected with surfaces which have aroused scientific interest are surface tension, surface waves, photoelectric emission, reflection, refraction, evaporation, adsorption, adhesion, thin films, detergents, catalysts, cell membranes, skin. All of these phenomena (...) are complex, interesting, and some of them are still far from completely understood. Are surfaces important for philosophy? An epistemologist might well answer affirmatively, thinking of Quine’s "surface irritations" as the basis of our knowledge of the physical world, or Berkeley’s theory of vision, or the view that we perceive a material object in virtue of suitable causal interaction with its surfaces. But at first sight it seems that there is not much of interest for an ontologist. In his work on surfaces, especially in the book of that name, Avrum Stroll has shown to the contrary that there is much ontological interest in surfaces} Every ontologist delights in a newly discovered or hitherto neglected member of the ontological zoo: surfaces are not exactly new, but they have been neglected, and we can be grateful to Stroll for bringing them to greater prominence. (shrink)