In philosophy, empiricism is a theory that states that knowledge comes only or from sensory experience. It is one of several views of epistemology, the study of human knowledge, along with rationalism and skepticism. Empiricism emphasises the role of empirical evidence in the formation of ideas, rather than innate ideas or traditions. However, empiricists may argue. Empiricism in the philosophy of science emphasises evidence as discovered in experiments, it is a fundamental part of the scientific method that all hypotheses and theories must be tested against observations of the natural world rather than resting on a priori reasoning, intuition, or revelation. Empiricism used by natural scientists, says that "knowledge is based on experience" and that "knowledge is tentative and probabilistic, subject to continued revision and falsification". Empirical research, including experiments and validated measurement tools, guides the scientific method; the English term empirical derives from the Ancient Greek word ἐμπειρία, cognate with and translates to the Latin experientia, from which the words experience and experiment are derived.
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, previous experimental results in order to engage in reasoned model building and theoretical inquiry. Philosophical empiricists hold no knowledge to be properly inferred or deduced unless it is derived from one's sense-based experience; this view is contrasted with rationalism, which states that knowledge may be derived from reason independently of the senses. For example, John Locke held that some knowledge could be arrived at through intuition and reasoning alone. Robert Boyle, a prominent advocate of the experimental method, held that we have innate ideas; the main continental rationalists were advocates of the empirical "scientific method".
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; 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 phantasiai. The Empiric school was allied with Pyrrhonist school of philosophy, which made the philosophical case for their proto-empiricism; the notion of tabula rasa connotes a view of mind as an blank or empty recorder on which experience leaves marks. This denies; the image dates back to Aristotle: What the mind thinks must be in it in the same sense as letters are on a tablet which bears no actual writing. Aristotle's explanation of how this was possible was not empiricist in a modern sense, but rather based on his theory of potentiality and actuality, experience of sense perceptions still requires the help of the active nous.
These notions contrasted with Platonic notions of the human mind as an entity that pre-existed somewhere in the heavens, before being sent down to join a body on Earth. Aristotle was considered to give a more important position to sense perception than Plato, commentators in the Middle Ages summarized one of his positions as "nihil in intellectu nisi prius fuerit in sensu"; this idea was developed in ancient philosophy by the Stoic school. Stoic epistemology emphasized that the mind starts blank, but acquires knowledge as the outside world is impressed upon it; the doxographer Aetius summarizes this view as "When a man is born, the Stoics say, he has the commanding part of his soul like a sheet of paper ready for writing upon." During the Middle Ages Aristotle's theory of tabula rasa was developed by Islamic philosophers starting with Al Farabi, developing into an elaborate theory by Avicenna and demonstrated as a thought experiment by Ibn Tufail. For Avicenna, for example, the tabula rasa is a pure potentiality, actualized through education, knowledge is attained through "empirical familiarity with objects in this world from which one abstracts universal concepts" developed through a "syllogistic method of reasoning in which observations lead to propositional statements which when compounded lead to further abstract concepts".
The intellect itself develops from a material intellect, a potentiality "that can acquire knowledge to the active intellect, the state of the human intellect in conjunction with the perfect source of knowledge". So the immaterial "active intellect", separate from any individual person, is still essential for understanding to occur. In the 12th century CE the Andalusian Muslim philosopher and novelist Abu Bakr Ibn Tufail included the theory of tabula rasa as a thought experiment in his Arabic philosophical novel, Hayy ibn Yaqdhan in which he depicted the development of the mind of a feral child "from a tabula rasa to that o