The Big Brain Theory presents a modern view of the universe. To demonstrate the consistency of this view, it retraces step by step and in a fully structured way the entire universe, from micro to macrocosm. After this, it performs a test to demonstrate how difficult it is to invalidate this view. Later, it uses this view to formulate hypotheses for questions such as: What exists? What are we? What is soul? Does God exist? What is life? What is death? All of this is done in an objective and coherent way without delving into any science. The Big Brain Theory is the first book that shows a totally feasible view of the reality.