Which of the following asserts that there is no single truth or reality?

The assertion that there is no single truth or reality is closely aligned with constructivism ontology. This perspective emphasizes that individuals construct their own understanding and meaning of the world through their experiences and interactions. From this viewpoint, reality is subjective and shaped by personal experiences, which means that multiple interpretations can coexist simultaneously. In essence, constructivism acknowledges the complexity of human experience and rejects the idea that there is an objective reality that can be universally understood or agreed upon.

In contrast, the other options present different philosophical stances. Positivism typically asserts that knowledge is gained through observable phenomena and that an objective reality exists, which can be understood through scientific inquiry. Idealism posits that reality is fundamentally mental and immaterial, while realism asserts that the world exists independently of our perceptions, thus supporting the notion of a singular, external reality that can be known. These distinctions highlight why constructivism ontology is the appropriate choice when discussing the nonexistence of a singular truth or reality.