  In this section we describe Sylvan’s work in moral philosophy. His seminal and frequently reprinted (1973; see also SEP entry “Environmental Ethics” Section 2) was, alongside Naess (1973), the first published work in environmental ethics and began a central debate in the area, one concerned with intrinsic value in nature. Elaborated on in Routley and Routley (1979b) and (1980a), this work developed arguments against what he termed “human chauvinism”—the view that humans are exceptional in being the sole locus of intrinsic value, all else having merely instrumental value. Alongside this work in environmental ethics more broadly, which was to continue until his death, he also published in defence of pacifism, against nuclear war, and was one of the first philosophers to point to the emerging moral issues associated with anthropogenic global warming.