In philosophy of science, there are several definitions of protoscience. Its simplest meaning involves the earliest eras of the history of science, when the scientific method was still nascent. Another meaning extends this idea into the present, with protoscience being an emerging field of study which is still not completely scientific, but later becomes a properscience. An example of it is the general theory of relativity, which started as a protoscience, but later was experimentally verified and became fully scientitific. Protoscience in this sense is distinguished from pseudoscience by a genuine willingness to be changed through new evidence, as opposed to having a theory that can always find a way to rationalize a predetermined belief. Philosopher of chemistry Jaap Brakel defines protoscience as "the study of normativecriteria for the use of experimental technology in science." Thomas Kuhn said that protosciences "generate testable conclusions but... nevertheless resemble philosophy and the arts rather than the established sciences in their developmental patterns. I think, for example, of fields like chemistry and electricity before the mid-18th century, of the study of heredity and phylogeny before the mid-nineteenth, or of many of the social sciences today." While noting that they meet thedemarcation criteria of falsifiability from Popper, he questions whether the discussion in protoscience fields "result in clear-cut progress". Kuhn concluded that protosciences, "like the arts and philosophy, lack some element which, in the mature sciences, permits the more obvious forms of progress. It is not, however, anything that a methodologicalprescription can provide.... I claim no therapy to assist the transformation of a proto-science to a science, nor do I suppose anything of this sort is to be had". The term prescientific means at root "relating to an era before science existed". For example, traditional medicineexisted for thousands of years before medical science did, and thus many aspects of it can be described as prescientific. In a related sense, protoscientific topics can be called prescientific, in which case the proto- and pre- labels can function more or less synonymously. Compare fringe science, which is considered highly speculative or even strongly refuted. Some protosciences go on to become an accepted part of mainstream science.
