<P> A central concept in science and the scientific method is that it must be empirically based on the evidence of the senses . Both natural and social sciences use working hypotheses that are testable by observation and experiment . The term semi-empirical is sometimes used to describe theoretical methods that make use of basic axioms, established scientific laws, and previous experimental results in order to engage in reasoned model building and theoretical inquiry . </P> <P> Philosophical empiricists hold no knowledge to be properly inferred or deduced unless it is derived from one's sense - based experience . This view is commonly contrasted with rationalism, which states that knowledge may be derived from reason independently of the senses . For example, John Locke held that some knowledge (e.g. knowledge of God's existence) could be arrived at through intuition and reasoning alone . Similarly Robert Boyle, a prominent advocate of the experimental method, held that we have innate ideas . The main continental rationalists (Descartes, Spinoza, and Leibniz) were also advocates of the empirical "scientific method". </P> <P> Vaisheshika darsana, founded by the ancient Indian philosopher Kanada, accepted perception and inference as the only two reliable sources of knowledge . This is enumerated in his work Vaiśeṣika Sūtra . </P> <P> The earliest Western proto - empiricists were the Empiric school of ancient Greek medical practitioners, who rejected the three doctrines of the Dogmatic school, preferring to rely on the observation of "phenomena". </P>

An important matter for the british empiricist was