"Science does progress toward more adequate understanding of the empirical world, but no pristine, objective reality lies "out there" for us to capture as our technologies improve and our concepts mature. The human mind is both an amazing instrument and a fierce impediment—and the mind must be interposed between observation and understanding. Thus we will always "see" with the aid (or detriment) of conventions. All observation is a partnership between mind and nature, and all good partnerships require compromise. The mind, we trust, will be constrained by a genuine external reality; this reality, in turn, must be conveyed to the brain by our equally imperfect senses, all jury-rigged and cobbled together by that maddeningly complex process known as evolution."