When words are considered in their relationship to the human, as acts--they become behavior. But when they are considered in terms of their relationship to one another, grammar, syntax, and so forth, they become language, the subject matter not of psychology but of the science of linguistics. Culture, therefore, is the name given to a class of things and events dependent upon symboling (i.e., articulate speech) that are considered in a kind of extra-human context. Man alone due to ability possesses culture. The question of whether the difference between the mind of man and that of animals is one of kind or of degree has been debated for many years, and even today reputable scientists can be found on both sides of this issue. But no one who holds the view that the difference is one of degree has adduced any evidence to show that animals are capable of a kind of behavior that all human beings exhibit. This kind of behavior may be illustrated by the following examples: remembering the Sabbath to keep it holy, classifying one's relatives and distinguishing one class from another (such as uncles from cousins), defining and prohibiting incest, and so on. There is no reason or evidence that leads one to believe that any animal other than man can have or be brought to any appreciation or comprehension whatever of such meanings and acts. Tylor argued long ago, a "mental gulf that divides the lowest savage from the highest ape" (Anthropology). A very large brain characterizes man, and it is reasonable to believe that the central nervous system, especially the forebrain, is the location of the ability to symbol. At some point in the evolution of primates a threshold was reached in some line, or lines, when the ability to symbol was realized and made explicit in overt behavior. There is no intermediate stage between symboling and non-symboling; an individual or a species is capable of symboling, or it is not.