Normality is imminently catastrophic. Climate change is a contemporary instantiation of the perpetual sense of crisis that characterises the human condition, and concepts such as sustainability and resilience serve as regulative ideals (cf. beauty, perfection, and truth) in the fight against ubiquitous unsustainability. Unsustainability is an aspect of time, and is thus, in Kantian terms, a fundamental schema underlying the categories of human understanding. Current growth will decay, therefore only as yet unforeseen adaptation and innovation can give humanity more time to encounter the next set of crises. On this account, the arts and humanities operate as a collective memento mori, reminding us of our fragility and fallibility. Only thus reminded can we act with the greatest possible care in the world, but this can never ensure "sustainable development", which remains an inherently paradoxical policy slogan.