How did 19th century philosophers/scientists answer the question "How can we know anything at all?"

Question

The first task in the development of every discipline is the act of defining exactly what that discipline is. For psychology, this definition began in the 18 ^th century with a consideration of “How can we know anything at all?” In your own words but correctly using all of the important vocabulary (from both the text and learning modules), explain in detail how 19 ^th century philosophers/scientists sought to answer this question.

Answer 1

Nineteenth-century philosophers and scientists tried to answer “How can we know anything at all?” by studying how knowledge develops through reason, experience, and perception. Rationalists believed some knowledge comes from the mind itself, while empiricists argued that knowledge begins with sensory experience. Thinkers such as John Locke described the mind as a tabula rasa, or blank slate, and associationists explained how simple experiences combine to form complex ideas.

Immanuel Kant brought these views together by arguing that knowledge begins with experience, but the mind actively organizes what we perceive. Scientists then began testing these ideas through physiology and psychophysics. Johannes Müller showed that sensation depends partly on which nerves are activated, while Hermann von Helmholtz argued that perception involves unconscious inference based on past experience. Ernst Weber and Gustav Fechner demonstrated that the relationship between physical stimuli and mental sensations could be measured.

Together, these ideas showed that knowledge is not simply copied from the outside world. It is created through the interaction of sensory experience, the nervous system, past learning, and the mind’s organizing processes. This helped establish psychology as a scientific discipline.