In 1884 Samuel Butler published a collection of essays entitled Remarks on George Romanes’ Mental Evolution, where he attempted to show how Romanes’ idea of mental evolution presented similarities with his theory of unconscious memory. By looking at Romanes’ work through Butler’s writing, this article will reevaluate some aspects of their works regarding the complex debate about memory, heredity, and instinct. This paper will explore the main differences and similarities between Romanes’ science and Butler’s writing on science both in terms of their ideas and contents. It will then look into their different professional relationships with Darwin and how this determined the professional and public reception of their theories.