Schooled Americans often think that humans should develop evidence-based beliefs. We prefer to decide what to believe by crafting a theory, gathering the evidence, analyzing it, and using it to confirm or disconfirm the theory. This scientific process works from the assumption that people can be rational, objective and separate from their study, and this itself is fundamentally a belief. Where is the evidence that confirms it and how much is there? Where is the evidence that disconfirms it and how much is there? I don’t know if anyone can answer these questions, but they got me asking more questions: do we really decide what to believe off of the data? Is evidence the sole determinant or one among many? Is data a deciding factor at all? Where do beliefs come from if not from data?E.O. Wilson addresses some of these questions in his book Biophilia. In The Time Machine chapter, Wilson brings the reader to 1859, when Charles Darwin faced off against Louis Agassiz in the correct explanation of how life works. While Agassiz maintained that God created all living species as they currently exist, Darwin spent decades in the details of how and why species change over time, and derived his Theory of Natural Selection from what the data told him. Agassiz used the dominant beliefs of the time to decide what to believe. Darwin used evidence. That’s how Wilson frames the difference between them. If Darwin’s theory is correct, why do people still believe in creationism? It seems that there is more going on here than just the linear “evidence decides belief” model. Let’s start with the opposite: “belief decides evidence”. The entire book Biophilia is a good example of the mutually reinforcing dynamic between beliefs and evidence. Wilson shares charming childhood stories of himself exploring the Brewton swamp in The Serpent. The excitement of engaging with a water moccasin snake inspired Wilson’s belief that we “will find little ultimate meaning apart from the remainder of life” (81), which further informed his career in science. Wilson could have denied the positive feelings that he felt as a child, but let himself believe what he felt was true and live his life on the foundation of biophilia. At the same time, some people may learn to believe that relationships with other life forms do not matter, and therefore withhold themselves from seeing that they do. Wilson’s point is that even those who believe this betray themselves just by being alive as relational, ecological selves. The microbiome, for example, is a collection of trillions of non-human cells that greatly shape each and every human experience. This state of being goes to show that all that makes up a “human” is complex and incomprehensible on its own terms.Again in The Time Machine, Wilson guides the reader from our normal, organismic, sense of time, to biochemical, ecological, and evolutionary time scales, which all shape our experience of reality. These ways of seeing nature are accessible to us through science and technology. However, our access does not imply that we know all that there is to know, or that we are getting closer to knowing all that there is to know. Whether because of the vastness and minuteness of the universe, our inescapable biases or something else entirely, humans are knowledgeable in ignorance and powerful in powerlessness. By recognizing this paradox, Wilson calls for humility when he says that “the truth is that we never conquered the world, never understood it; we only think we have control” (139). How, then, do we decide what to believe? Statistical and mathematical models are certainly useful tools for deciding, but they are neither exclusive nor foundational. Biophilia suggests that we decide through uncertainty and through conversation – not only negotiating what to believe among diverse perspectives and people, but also with the entire diversity of life on Earth. That affirmation of the interdependence of all living beings is why we must protect and honor our cosmic home.