160:2.1

There are just two ways in which mortals may live together: the material or animal way and the spiritual or human way. By the use of signals and sounds animals are able to communicate with each other in a limited way. But such forms of communication do not convey meanings, values, or ideas. The one distinction between man and the animal is that man can communicate with his fellows by means of symbols which most certainly designate and identify meanings, values, ideas, and even ideals.