Protoscience denotes a fringe science that has limited acceptance in the mainstream scientific community but is nonetheless rooted in established scientific principles and thus has potential for being more widely accepted. It can be defined as "any set of beliefs or theories that have not yet been tested adequately by the scientific method but which are otherwise consistent with existing science, [thus being] a new science working to establish itself as legitimate science". Fringe science ideas that have been rejected are classified as pseudoscience, not protoscience.

In the philosophy of science, a “protoscience” is an area of scientific endeavor that is in the process of becoming established. Protoscience is distinguished from pseudoscience by its standard practices of good science, such as a willingness to be disproven by new evidence, or to be replaced by a more predictive theory. Sometimes scientific skeptics refer to protoscience as “pathological sciences”. “Protoscience” is a term sometimes used to describe a hypothesis which has not yet been tested adequately by the scientific method, but which is otherwise consistent with existing science or which, where inconsistent, offers reasonable account of the inconsistency. Some protosciences go on to become an accepted part of mainstream science, e.g., astrology and alchemy (at a time before invention of the scientific method), might be called “protosciences” by historians of science, but after the invention of the scientific method, when some practitioners refused to adopt the scientific method, the fields were then labeled “pseudoscience”. Several sciences started as branches of philosophy: mathematics, natural philosophy, economics, psychology, sociology, and the same may end up, historically, being the case for some cultural, traditional, or ancient practices. A “protoscience” may be a field where the hypothesis presented may or may not be in accordance with the known evidence at that time, and a body of associated predictions have been made, but the predictions have not yet been tested, or cannot be tested, due to current technological limitations. Such was the case for general releativity at the time of its proposal, which is now considered science, and the case for string theory, which at the time of this article writing is a protoscience.

Etymology

proto- + science

protoscience (plural protosciences)

1. an unscientific field of study which later becomes a science (e.g. astrology becoming astronomy and alchemy becoming chemistry).
2. a field of study at the initial phase of the scientific method, involving information gathering and hypothesis formulation, but is not yet falsifiable, or if it is, its predictions have not yet been observed.