During my six years of teaching “Physics today” to non-physics major students at Peking University, I have gradually come to understand the essence of instruction. That is, physics must be viewed from a high and long-reaching vantage. Students must be shown clearly the basic outline, fundamental points, and vigor of physics. By discussing some important events in the history of physics, we should let students understand how scientists deal with problems in their research, and from the statements and actions of scientists understand how to do research. By this means, we can make the students realize what is of the most importance in science, and train them to think creatively. Comments and criticisms from colleagues are warmly welcomed.