Abstract
According to the iterative conception, each set is formed out of sets that are, in some sense, prior to it. Because priority plays an essential role in explanations of why contradiction-inducing sets, such as the universal set, do not exist, the success of these explanations depends on our ability to make sense of the relevant priority relation. I argue that attempts to do this have fallen short: understanding priority in a straightforwardly constructivist sense threatens the coherence of the empty set and raises serious epistemological concerns; but the leading realist interpretations–ontological and modal interpretations of priority—are deeply problematic as well. I conclude that the purported explanatory virtues of the iterative conception are, at present, unfounded.
C double bonds such as stilbene derivatives. Comparing the weathering conditions between light only and light plus water exposure, it was found that weathering in the presence of water significantly enhances the degradation of lignin. The Raman images exhibited that the degree of lignin degradation by light only exposure is according to the depth. However, in the case of light plus water exposure, lignin degradation in the outermost cell walls proceeded from both the exposed surface side and the lumen side of the cell walls. This study is expected to potentially promote development of more effective and efficient methods to protect wood surfaces against weathering.
