Which term best describes the belief that exclusive reliance on measurable phenomena defines reality?

The term that best describes the belief that exclusive reliance on measurable phenomena defines reality is naturalism. This philosophical standpoint asserts that everything arises from natural properties and causes, and supernatural or spiritual explanations are excluded or discounted. Naturalism is grounded in the idea that observable and measurable phenomena are the only valid data that can define our understanding of the universe, thus prioritizing empirical evidence and scientific inquiry.

Subjectivism, on the other hand, emphasizes personal perspectives and experiences as the key to understanding reality, often disregarding measurable phenomena. Relativism suggests that truth and morality are contingent on cultural, social, or personal circumstances, thereby not prioritizing measurable phenomena as the sole basis for defining reality. Idealism posits that reality is mentally constructed or immaterial, placing emphasis on ideas and consciousness over measurable entities.

Naturalism distinctly focuses on measurable and observable phenomena as the foundation for understanding reality, making it the correct choice in this context.