This is my original doctoral dissertation, which I submitted to New York University and successfully defended in 1978. The dissertation presents my anthropotropic theory of media evolution (anthropo = human; tropic = towards) which argues that as media evolve, they become increasingly human in function. Thus, telegraph gives way to telephone (we hear words not dots and dashes), photography changes from black-and-white to color, etc. The theory also explains why some media survive the advent of successor media and others do not: radio survived the advent of television because hearing without seeing is a natural mode of human communication (it gets dark every night and we still hear, we can easily close our eyes and continue to hear), whereas silent movies were obliterated by talkies (it is very difficult in the natural world to see without hearing something or other). The theory also predicts the creation of media that will enable us to access all kinds of information from any place in the world, any time, regardless of where we and that information might be - or, exactly what we now do with smartphones.