The fact is that no contradictory aspect can exist in isolation. Without its opposite aspect, each loses the condition for its existence. On Contradiction (1937)
Qualitatively different contradictions can only be resolved by qualitatively different methods. On Contradiction (1937)
Opposition and struggle between ideas of different kinds constantly occur within the Party; this is a reflection within the Party of contradictions between classes and between the new and the old in society. If there were no contradictions in the Party and no ideological struggles to resolve them, the Party's life would come to an end. On Contradiction (1937)
Every difference in men's concepts should be regarded as reflecting an objective contradiction. Objective contradictions are reflected in subjective thinking, and this process constitutes the contradictory movement of concepts, pushes forward the development of thought, and ceaselessly solves problems in man's thinking. On Contradiction (1937)