For almost 2,000 years Aristotle’s philosophy was taught in schools and accepted by educated people. In the sixteenth century doubts about Aristotle’s science increased. A number of philosophers, including those whom today we would call scientists, actively opposed Aristotle’s dominance of the curriculum in schools. Englishman Francis Bacon (1561-1626) developed what we today would call the scientific method in opposition to Aristotle’s philosophy. In 1612 Galileo (1564-1642) published “Discourse on Floating Bodies” in which he envisioned atoms as infinitely small particles, views that he later expanded in “The Assayer” (1623) and, more completely, in “Discourses on Two New Sciences” (1638). Nevertheless, the debate over whether atoms, much too small to see, really existed or were just a successful model of matter continued for another two centuries.