 First, what does it mean to say biodiversity has intrinsic value (Vucetich, Bruskotter, &amp; Nelson 2015)? Ethicists debate what is intrinsic value and what might have it (O’Neill 1992). Some argue that intrinsic value is the value something has in virtue of its intrinsic properties (Moore 1903) A property is intrinsic roughly if it is had by something independent of other objects (see entry on  intrinsic vs. extrinsic properties).  However, many properties that make species valuable include ones like beauty and rarity which are arguably extrinsic (Russow 1981). Other philosophers argue that intrinsic value is what we value for its own sake (Ewing 1947; Lewis 1989). What is special about intrinsic value is how something is valued not the properties of thing so valued. But this is says nothing about what the attitude of valuing is and it raises other difficult questions. Some think intrinsic value does not depend on valuers whatsoever. But this appears to assume a strong form of moral realism about value, which some metaethicists would deny (Blackburn 1993; Gibbard 1992).