The Interconnectedness of All Things
Wilson's entire premise is based upon his belief that everything in the natural universe is somehow connected. Therefore the universe will not contradict itself, so scientists and philosophers would do well to consider broadening their vision. Wilson devotes the majority of his text to supporting this claim. He points out the natural state of order and organization which is present in nature. He argues that that order extends much farther than we give it credit so that people should compare any idea within a given field to knowledge of other fields for a more holistic perspective. He wants to unify and rectify all the fields of knowledge so that they can be helpful to one another.
Reliance upon the Past
Wilson bases all of his principal tenets upon the idea that we can understand the universe today in light of the universe yesterday. All of his arguments assume that the universe has remained consistent throughout history, consistent to a few unknown principles which govern its functioning. Wilson believes that those principles, once discovered, can readily explain literally everything. Relying upon conclusions and discoveries of philosophers and scientists of the past, Wilson's work is rooted in historical fact. He wants to establish is logos on top of the logos of great thinkers who have preceded him.
The Common Ethical Principles of Humanity
Much of Wilson's book is devoted to ethics. Given his commitment to intersectionality, Wilson believes that each field of study relates to the next. He encourages his readers to consider how lost ethics have become among other pursuits. He argues that ethics applies to every single field. In fact for scientists to be truly successful in their fields, they must first understand ethics since any discoveries within their field of study must be consistent with these principles. More importantly, Wilson argues that the petty differences which cause people in one community to antagonize another community would be eliminated with a renewed focus upon universal ethics. He believes that everything within the universe -- all matter -- behaves according to a set of ethical principles which also should govern our actions as people.
Persuasion
Wilson is writing from a persuasive perspective. After his years as a scientist, he believes he has identified a flaw in the present system. He's trying to persuade his readers to agree that the status quo must be altered in favor of a more holistic approach to study. This persuasiveness manifests in his appeals to history for ethos and logos. He wants to place his arguments within a long train of human experience so as to better quantify to magnitude of the issues present.