The question asks for what the two paradigms share, so the answer must be a goal each of them would accept.

Positivism holds that a single objective reality exists and can be measured directly; the researcher stands apart from it, tests hypotheses and seeks law-like generalisations, typically through quantitative and experimental methods.

Post-positivism retains the commitment to an objective reality but denies that it can ever be known with certainty. Observation is theory-laden and every measurement is fallible, so knowledge is built by falsification and triangulation and remains probable rather than proved.

Despite that disagreement about certainty, both are empirical paradigms directed at the same end — to discover new knowledge and contribute to the understanding of phenomena. That is the goal they hold in common.

Eliminating subjectivity entirely is a positivist aspiration only; post-positivism explicitly concedes that the researcher's background and theory shape observation, and answers that with rigour and peer scrutiny rather than with a claim of total objectivity.

Prioritising personal opinions over empirical evidence is rejected by both, since evidence is the arbiter in each paradigm.

Avoiding data altogether contradicts both, as each is empirical by definition.

Hence the shared goal is to discover new knowledge and contribute to the understanding of phenomena.