This work explores the evolution of humans, presenting evidence for the descent of man from lower forms of life. It examines the development of physical and mental traits, comparing human capabilities with those of other animals. The text discusses the role of natural selection and introduces the concept of sexual selection, analyzing how these processes have shaped human characteristics and behaviors. The author addresses the moral and intellectual faculties of humans, their social instincts, and the implications of these traits in the context of civilization. The work is structured into distinct parts, focusing on the origin of man, sexual selection, and the relationship between these themes.