Why do some people find a book very deep, others - empty, others - abstruse? Why, when rereading a book, do you always discover something you didn’t notice before? Why does someone understand all shades of meaning, see what is hidden between the lines, hear the music of words, feel their taste, color and smell, while others remain deaf to them? Why does someone understand the contents of a textbook the first time, while others need to explain it repeatedly? To tune in to the author’s “wave” and understand more, the ability to read actively is required. This is precisely why Mortimer Adler, an American philosopher, editor and teacher, wrote his book, who devoted his entire life to teaching people to love and understand books (he later headed the editorial board of the Britannica encyclopedia). The book is needed by those who want to develop their abilities. to the multifaceted perception of the text, as well as those who would like to write books themselves so as to be correctly understood, and those who are engaged in editorial work.