What did Brentano consider to be a valid method of studying immediate experience?

Brentano believed that direct inner observation is a valid method of studying immediate experience. He posited that this approach allows individuals to examine their own mental processes and experiences firsthand, which he considered crucial for understanding consciousness and psychological phenomena. Brentano viewed psychology as a descriptive science that should focus on the phenomena of experience as they present themselves, rather than relying on external measures or interpretations. This method aligns with his emphasis on the subjective nature of mental experiences and the importance of firsthand insight into one’s own thoughts and feelings.

In contrast to Brentano's perspective, indirect inner observation and objective observation prioritize external validation or observable behaviors, which can detract from the immediacy and subjectivity of inner experience. Experimental introspection, while useful in some contexts, implies a structured and potentially biased methodology that may not capture the authentic essence of immediate experience as Brentano intended. Thus, direct inner observation stands out as the approach that best embodies Brentano's mission to understand the intricacies of conscious experience from the subject’s own perspective.