Synchronicity is considered pseudoscience because it is neither testable nor falsifiable. However, synchronicity itself is considered neither testable nor falsifiable. One must always add auxiliary hypotheses in order to make testable predictions. Both natural and social sciences use working hypotheses that are testable by observation and experiment. Leontief was primarily interested in applied economics and testable hypotheses. A hypothesis with no supporting, objective, testable evidence is not an objective, scientific claim. Conjecture is related to hypothesis, which in science refers to a testable conjecture. Glashow is a skeptic of superstring theory due to its lack of experimentally testable predictions. This hypothesis leads to a larger number of testable predictions. Science is a systematic enterprise for obtaining knowledge through testable explanations and predictions. Linnaeus was the first to frame the balance of nature as a testable hypothesis. Psychoanalysis is a theory that is not easily testable. Using quantitative methods, it is possible to give precise and testable expression to qualitative ideas. However, much care would be needed to disentangle tautological from testable aspects. The productive mindset seeks out valid knowledge that is testable.