It is definitely fair to say that the invention of the printing press was “revolutionary,” and perhaps even the most important invention up to that point in the history of humankind.
Before the printing press made inexpensive, portable information possible, ideas were spread almost exclusively by word of mouth. There were some books, but they were expensive, rare, and very labor intensive to create.
Just look at what happened when the written word became accessible to almost everyone:
1. The Renaissance: This era changed the European world artistically, culturally, and philosophically. One name should be all we need to hear to convince us—William Shakespeare. Although his works were meant primarily to be watched, print made it possible to preserve and distribute almost everything he wrote. To think that he is still the most highly regarded writer in the history of the English language is amazing. It certainly would not have been possible without printing presses. Shakespeare, or course, is only one example. There were many, many others who contributed to the changing face of European culture.
2. The rise of the middle class: Around this time the middle class began to swell in Europe. Print led to a greater degree of literacy, which in turn led to greater opportunities for more people as Europe began to lurch toward greater economic and industrial power.
3. More political autonomy: Political philosophers like Locke, Montesquieu, and Rousseau began to exert an influence that helped more people gain political power. The ability to read and understand their ideas gave people conceptual knowledge about political theory on an unprecedented scale. The spread of information became the spread of ideas and spread of unified action.
4. Scientific advancement: Ideas that had previously been considered heretical (like the earth moving around the sun) now gained wider acceptance as more people could read about them for themselves. This in turn led to more scientific inquiry and willingness. Once Isaac Newton published his three laws of motion in 1686, the pursuit of scientific knowledge exploded and the world was never the same.
To truly appreciate how “revolutionary” print turned out to be, just look at what the world was like before and after the advent of the printing press in Europe. Before the press, history changed relatively little for many centuries (they are called the Dark Ages for a reason—there was not much development of cultural or scientific thought for a long time). In the five or so centuries since then, everything has changed and changed again and changed some more.