This paper is a contribution to our understanding of Alfred Russell Wallace, for whom this year marks the 100th anniversary of his death. I seek to explore Wallace's scientific contributions that resulted from his eight years' residence in the Malay Archipelago and his impact on theoretical biology. Wallace's enthusiasm for natural science and cheerful fearlessness made him well suited to exploring the equatorial archipelago. His field notes and specimen collection alone added monumental data to the understanding of our natural world, the sum total of his Malay Archipelago collection is 125,660 specimens. Focusing on Wallace's most notable contributions to the development of biological theory, including his letter to Charles Darwin on natural selection and his influence on the study of biogeography, I argue that his time in this fertile region yielded depth and breadth of knowledge that has catalyzed sustained scientific advancement in theoretical biology, proving Wallace's worth in the history of science.