His work is important to study from an historical perspective in order to see how psychology grew into what it is today, in the same way that it’s important that we learn about outdated concepts like tabula rasa and phrenology in order to better understand what is correct. The fact that he applied so much of his own subjective thoughts to his brand of psychology shows us how we, as potential future psychologists, also have the same capacity to search for confirmatory evidence and eschew disproving evidence in search of a theory. He’s a great example of what not to do when it comes to psychology.