Why did Putnam think that reality can be described in more than one valid way?

Hilary Putnam argued that reality can be described in more than one valid way because he rejected the "metaphysical realist" view that there is a single, uniquely correct, mind-independent representation of the world.12

Instead, Putnam emphasized the autonomy and complexity of human language, noting that the same reality can be described through multiple, equally legitimate conceptual schemes or theories. He pointed to the prevalence of equivalent theories in science and mathematics as evidence; these theories may differ in their ontologies—such as one describing forces while another describes fields—yet both successfully predict and explain the same phenomena.12

By adopting what he termed "internal realism," Putnam maintained that while we cannot access a "ready-made" world independent of our descriptions, this does not lead to subjectivism or relativism. He argued that truth under a description remains objective, as it is anchored in external reality through causal connections and social practices rather than being purely a mental construct.12