This article explores Warren Buffett's evolving investment philosophy, detailing his three stages of development: starting with his early "cigar butt" value investing learned from Benjamin Graham, progressing to an embrace of growth-oriented investments like Coca-Cola, and finally reaching a "mature" stage focused on businesses with "franchise" characteristics and high returns on capital, exemplified by Apple. It highlights the profound influence of philosophical thought on Buffett, tracing his emphasis on independence to Ralph Waldo Emerson, his rationality and resilience to Stoicism through Graham, and his empirical wisdom and pragmatism to Charlie Munger. Ultimately, the text argues that Buffett's success stems from a commitment to lifelong learning, decisive action, and unwavering integrity, all rooted in the principle of "being an independent self."