Жаңазеландиялық философ және логик ғалымның өмірі мен еңбектері

New Zealand–born philosopher

He died on 16 June 1996 of a massive heart attack. Together with Robert K. Meyer, Routley turned this into semantics for a large number of logical systems. Their work in logic work helped make ANU a center for the study of non classical logic in general. Routley's work had a particular influence on Graham Priest, a well known proponent of non classical logic; Sylvan and Priest edited a well regarded volume on the topic. Priest in turn influenced Sylvan; they met in 1976 at the Australasian Association of Logic conference in Canberra at a time when Sylvan was doing novel work on dialetheism, the view that some contradictions are true. Not long after meeting Priest, and then investigating a logic capable of handling such true contradictions, Sylvan also endorsed the view. Sylvan's studies ranged over a variety of topics in logic and the philosophy of logic. He wrote important papers on free logic, general modal logic, and natural deduction systems. However, much of his most important work in logic was dedicated to relevant logic, for which he authored numerous papers (both technical and expository). From early in his career (and for many years after), Sylvan defended a sophisticated Meinong inspired ontology (which he called "noneism"), first presented in his 1966 paper, "Some Things Do Not Exist." After several more papers in the 1970s, the theory was given a book length treatment in 1980, Exploring Meinong's Jungle and Beyond. The view—also defended in recent years by Priest—utilizes a modal theory including "impossible worlds" to deal with supposed objects, like the "round square." Sylvan's formulation is logically consistent, and avoids certain paradoxes associated with Meinong's original ontology; although, like many Meinongian views, it faces criticism due to its presumed ontological implausibility.

Outside of logic and metaphysics, Sylvan was a proponent of so called deep environmental ethics in the study of environmental ethics (following shallow/deep distinction formulated by Arne Næss). In his important 1973 paper "Is There a Need for a New, an Environmental, Ethic? ", he defended a then unorthodox account of the intrinsic value of the non human, natural world. For this he was sometimes considered a defender of deep ecology, but he was in fact very critical of much of the domain. Further, Sylvan spoke of supporting "regulated markets without capitalism." Beginning in the 1970s, Sylvan published several other notable articles and books on environmental ethics and issues, and he co authored the 1994 book The Greening of Ethics with David Bennett. From his work in environmental ethics, Sylvan took an interest in anarchism, contributing an often cited entry on the subject to A Companion to Contemporary Political Philosophy. Over 170 boxes of Sylvan's papers can be accessed from the Fryer Library collection of The University of Queensland Library.