him playing drums in the foreword. Even though the books were not adopted by universities as textbooks, they continue to sell well because they provide a deep understanding of physics. Many of his lectures and miscellaneous talks were turned into other books, including The Character of Physical Law, QED: The Strange Theory of Light and Matter, Statistical Mechanics, Lectures on Gravitation, and the Feynman Lectures on Computation. Feynman wrote about his experiences teaching physics undergraduates in Brazil. The students' studying habits and the Portuguese language textbooks were so devoid of any context or applications for their information that, in Feynman's opinion, the students were not learning physics at all. At the end of the year, Feynman was invited to give a lecture on his teaching experiences, and he agreed to do so, provided he could speak frankly, which he did. Feynman opposed rote learning or unthinking memorization and other teaching methods that emphasized form over function. Clear thinking and clear presentation were fundamental prerequisites for his attention. It could be perilous even to approach him unprepared, and he did not forget fools and pretenders. In 1964, he served on the California State Curriculum Commission, which was responsible for approving textbooks to be used by schools in California. He was not impressed with what he found. Many of the mathematics texts covered subjects of use only to pure mathematicians as part of the "New Math". Elementary students were taught about sets, but: In April 1966, Feynman delivered an address to the National Science Teachers Association, in which he suggested how students could be made to think like scientists, be open-minded, curious, and especially, to doubt. In the course of the lecture, he gave a definition of science, which he said came about by several stages. The evolution of intelligent life on planet Earth—creatures such as cats that play and learn from experience. The evolution of humans, who came to use language to pass knowledge from one individual to the next, so that the knowledge was not lost when an individual died. Unfortunately, incorrect knowledge could be passed down as well as correct knowledge, so another step was needed. Galileo and others started doubting the truth of what was passed down and to investigate ab initio, from experience, what the true situation was—this was science. In 1974, Feynman delivered the Caltech commencement address on the topic of cargo cult science, which has