Summary

The scala naturae (latin for ‘natural ladder’) is a concept of the order of natural forms that is often referred to as the great chain of being. It dates from medieval Christianity, and applies a rigid hierarchical organization to all matter and life. At the bottom of this hierarchy is earth, while God occupies the pinnacle. When applied to various forms of life, the hierarchy takes a very intuitive form, beginning with simple organisms which are followed by invertebrates, and then the vertebrates are placed in a relatively intuitive ‘evolutionary’ sequence (amphibians, reptiles, ‘lower’ mammals, ‘intermediate’ mammals and ‘higher’ mammals, e.g. primates). Perhaps not surprisingly, humans placed themselves at the pinnacle of this ‘tree of life’ (see Figure 19.1).

The earliest versions of the scala naturae predate Charles Darwin by several centuries, and despite the fact that over 150 years have passed since the original publication of The Origin of Species (1859), current notions of evolution are often imbued with elements of the scala naturae. While such hierarchical conceptualizations are apparently quite seductive, these intrusions of the scala do not serve theories of comparative cognition (Hodos and Campbell,1969).

This chapter explores several cases in which the visual cognition of animals appears to surpass that of humans. These cases are quite naturally considered paradoxical, but the reader is encouraged to consider why any instance of superiority of non-human visual cognition is so readily regarded as paradoxical.