The word 可以 is formed by combining two independent characters, each with its own core meaning, into a single cohesive unit. The first character, 可, carries the inherent idea of "may" or "to approve", while the second, 以, originally conveyed "to use" or "by means of". Their fusion creates a compound where their individual semantic fields blend, evolving from a literal sense of "permissible to employ" into the modern, holistic concept of "can" or "to be allowed", representing possibility and permission as a unified idea.