Behind the Mirror: A Search for a Natural History of Human Knowledge (German: Die Rückseite des Spiegels, Versuch einer Naturgeschichte menschlichen Erkennens) is a 1973 book by the ethologist Konrad Lorenz.

[1] Lorenz shows the essentials of a lifetime's work and summarizes it into his very own philosophy: evolution is the process of growing perception of the outer world by living nature itself.

One of the key positions of the book included the criticism of Immanuel Kant, arguing that the philosopher failed to realize that knowledge, as mirrored by the human mind is the product of evolutionary adaptations.

[2] Lorenz summarizes his life's work into his own philosophy: Evolution is the process of growing perception of the outer world by living nature itself.

In the book, Lorenz uses the mirror as a simple model of the human brain that reflects the part of the stream of information from the outside world it is able to "see".