We briefly discussed George Santayana's essay on Lucretius maybe a year or so ago. His essay was in fact taken from a book called Three Philosophical Poets—Lucretius for the materialist or "natural" view, Dante for the supernatural, and Goethe for the Romantic. I have not read these other two essays. It might be worth looking over them as they relate to this conversion.
I have read nearly everything of significance that came out of American Transcendentalism—the major figures as well as the lesser lights, including their diaries and journals, and the letters they exchanged. This was my major obsession in college, and I can still read these authors and find them occasionally refreshing. I'm more likely now to find them unhelpfully obscurantist.