The invention attributed to Johannes Gutenberg that revolutionized the spread of knowledge was the printing press, developed in the mid-15th century. Gutenberg's printing press introduced movable type, which allowed for the mass production of books, making literature and information more accessible than ever before. This technological advancement significantly lowered the cost of printing and facilitated the rapid dissemination of ideas, contributing to the spread of literacy and education across Europe. It played a crucial role in the Renaissance, the Reformation, and the Scientific Revolution by enabling the sharing of knowledge and ideas, ultimately transforming European society and culture.