Between the mid-19th century and the mid-20th century, scientific progress experienced constant growth. Two scientists, Darwin and Freud, made significant contributions to their field. Both scientists developed theories that changed people's thinking in many ways. Between 1850 and 1950, traditional ways of thinking about religion, morality, and human behavior were changed by Charles Darwin and Sigmund Freud. Darwin challenged traditional ways of thinking by presenting his theory of biological evolution. Before Darwin's discoveries, it was believed that every creature on earth was divinely created specifically by God. Darwin's theory held that all life came from a single species. A part of this species would then randomly develop characteristics that are not found in certain other members, and the adaptations would allow the species to survive or prevent it from surviving. Over time, these changes would give rise to many completely different species that struggled to survive. The only creature that would survive would be the one best adapted to random evolutionary changes. Changing ways of thinking about religion, Darwin refuted traditional thinking about religion by providing scientific evidence demonstrating that what many believed to be true was actually false. Darwin also led to a change in the view of human behavior. Darwin's theory was later applied to the human race, as many saw it as competition between countries and companies. Known as Social Darwinism, it asserted that only the "fittest" would be able to survive while others could not. Leading to an imperialist point of view, it depicts countries that were not a European power as weaker, because they were not up to ... middle of paper ... mother's love . These ideas led to greater acceptance, as everyone was expected to have these natural drives and desires. Freud changed traditional thinking through his studies of the human subconscious and the workings of the mind. Freud and Darwin changed the way people viewed religion, human behavior, and morality through their scientific discoveries. Freud theorized that the unconscious mind and the rational mind were in conflict with each other, with the morality believed to prevent unconscious desires from dominating the mind. Charles Darwin theorized that all life originates from a single species, which reproduces and evolves over time to adapt to survive, causing the creation of other species as the differences widen. Between 1850 and 1950, science and human perception of everyday characteristics were radically changed by the two scientists..