The development of the scientific method has made a significant contribution to how knowledge of the physical world and its phenomena is acquired.  To be termed scientific, a method of inquiry must be based on gathering observable and measurable evidence subject to specific principles of reasoning and experimentation.  The scientific method consists of the collection of data through observation and experimentation , and the formulation and testing of hypotheses .  Science, and the nature of scientific knowledge have also become the subject of Philosophy . As science itself has developed, scientific knowledge now includes a broader usage  in the soft sciences such as biology and the social sciences – discussed elsewhere as meta-epistemology , or genetic epistemology , and to some extent related to " theory of cognitive development ". Note that " epistemology " is the study of knowledge and how it is acquired. Science is "the process used everyday to logically complete thoughts through inference of facts determined by calculated experiments." Sir Francis Bacon was critical in the historical development of the scientific method; his works established and popularized an inductive methodology for scientific inquiry. His famous aphorism, " knowledge is power ", is found in the Meditations Sacrae (1597).