The quote "believing is seeing" is often attributed to the American psychologist William James. However, it is worth noting that the more common saying is actually "seeing is believing," which implies that people tend to believe something once they see evidence of it. This phrase has been used in various contexts and may not be directly linked to a specific psychologist's work.
On the other hand, William James, who was a prominent figure in psychology and philosophy, discussed the relationship between belief and perception in his works. He emphasized the idea that our beliefs and expectations can influence how we interpret the world around us. This concept aligns with the notion that our mental states can influence our perceptions and the way we see the world.
While "believing is seeing" is not a direct quote from William James, his contributions to psychology have certainly explored related themes concerning the role of beliefs and perceptions in shaping our experiences.