The Fundamental Assumptions of Science Science is based on two phenomena which every scientist agrees are true, and every experiment and scientific observation presumes are true. They are externality and corroboration. Externality is the perception that there is a world external to us. Something is out there that merits investigation, something that we perceive and experience. Science may or may not succeed in accurately describing this external world, but the certainty that it exists motivates the search.
Corroboration is the tendency of our perceptions to reflect and confirm our preconceptions.
What we assume to be true will appear to be true. Our expectations somehow modify our perceptions, and make us see things their way. We know that these twin assumptions of externality and corroboration are fundamental to science because they drive the scientific method . The scientific method is designed to foil corroboration, so that the scientist can see the external world, not as she preconceives it to be, but as it truly is. Thus, in making an observation the scientist intentionally suspends his preconceptions about what he is observing, assuming an attitude of objectivity.