The is not an attempt to provide an overview of theories in communication. Nor is it an attempt to provide a complete picture of approaches to communication theory. The book is an attempt to defend a very general empiricist approach to the scientific study of communication. The author is referring to the most general notion of empiricism, that we can come to some knowledge about the world through the use of our perceptions. Empiricism in these senses has taken quite a critical beating over the centuries, but in the sense in which he uses this term here it remains alive and well and prepared to serve as the foundation for the scientific study of communication, as it has for several decades. Secondly, the book is an attempt to defend a 'conventional' view of scientific theory. Thirdly, the book is an attempt to introduce into the mainstream of communication scholarship an approach to the philosophy of science known as 'scientific realism'. Fourthly, the book is a small part of the attempt to close some of the gaps between different sub-areas within communication science.