Complex sentence: In Kuhn's model, different paradigms represented entirely different and incommensurate assumptions about the universe, and was uncertain about whether paradigms shifted in a way which necessarily relied upon greater attainment of truth.
Split into simpler sentences: In Kuhn's model, different paradigms represented entirely different and incommensurate assumptions about the universe. The mode was thus uncertain about whether paradigms shifted in a way which necessarily relied upon greater attainment of truth.