It is widely agreed that species are valuable, and that this value justifies their protection. However, there are different views regarding what sorts of value they possess and the bases on which they possess it. In this chapter I consider several different types of value that species have been thought to have, and for each type assess whether it is reasonable to believe that they do, in fact, have that value. Because species conservation practices and policies are ultimately justified by their preserving the value of species or biodiversity, a clear understanding of the nature and basis of that value is necessary for evaluating them.
Types of value
Typologies divide and organize conceptual terrain. Most typologies are conventional and programmatic. This one is no different. It is a typology of value, not the typology. The types are not mutually exclusive. An entity, including a species, might possess value of more than one type.
The broadest categories of value are instrumental and final.2 Instrumental value is the value that something – an entity, experience, act, or state of affairs – has as a means to an end. It is usefulness value. The extent to which something has instrumental value is dependent upon the goals or ends of others, human or nonhuman. Thus, a thing’s instrumental value can differ from individual to individual (or entity to entity). Yard sales, for example, are predicated on the fact that something one person no longer needs can be of use to someone else; and acidic soil is conducive to the flourishing of blueberry bushes, but not to the flourishing of tetras.