First Principles

CORE DEFINITION

In philosophy and science, a first principle (or first principles) refers to a basic proposition that cannot be deduced from any other proposition or assumption. The concept originates in philosophy from Aristotle's doctrine of the 'first cause', while in Kantian philosophy, its corresponding form is called a 'postulate'. In mathematics and formal logic, first principles manifest as 'axioms' or 'postulates', constituting the absolute starting point of logical deduction. In physics and other scientific fields, if the research process is entirely based on fundamental physical laws, without relying on empirical models or parameter fitting, it is referred to as 'from first principles' or 'ab initio'. First principles thinking is a way of thinking that involves deconstructing a complex problem down to its most basic axioms and then reasoning up from those axioms to construct a solution. The process involves not only downward analysis and logical reconstruction of the problem but also rigorous cross-validation of conclusions to ensure they conform to physical laws. In this process, physicists often carefully handle counterintuitive inferences, using intense argumentation to discern whether they are limitations of cognition or breakthroughs to new knowledge.