Man, the Unknown (L'Homme, cet inconnu) is a best-selling 1935 book by Alexis Carrel where he endeavours to outline a comprehensive account what is known and more importantly unknown of the human body and human life. The book elucidates problems of the modern world, and possible routes to a better life for human beings.
For Carrel, the fundamental problem was that
[M]en cannot follow modern civilization along its present course, because they are degenerating. They have been fascinated by the beauty of the sciences of inert matter. They have not understood that their body and consciousness are subjected to natural laws, more obscure than, but as inexorable as, the laws of the sidereal world. Neither have they understood that they cannot transgress these laws without being punished. They must, therefore, learn the necessary relations of the cosmic universe, of their fellow men, and of their inner selves, and also those of their tissues and their mind. Indeed, man stands above all things. Should he degenerate, the beauty of civilization, and even the grandeur of the physical universe, would vanish. ... Humanity's attention must turn from the machines of the world of inanimate matter to the body and the soul of man, to the organic and mental processes which have created the machines and the universe of Newton and Einstein
Man The Unknown