Protoscience vs. Pseudoscience — What's the Difference?

In the philosophy of science, there are several definitions of protoscience. Its simplest meaning (most closely reflecting its roots of proto- + science) involves the earliest eras of the history of science, when the scientific method was still nascent.

Pseudoscience consists of statements, beliefs, or practices that claim to be both scientific and factual but are incompatible with the scientific method. Pseudoscience is often characterized by contradictory, exaggerated or unfalsifiable claims; reliance on confirmation bias rather than rigorous attempts at refutation; lack of openness to evaluation by other experts; absence of systematic practices when developing hypotheses; and continued adherence long after the pseudoscientific hypotheses have been experimentally discredited.The demarcation between science and pseudoscience has philosophical, political, and scientific implications.

An unscientific or pseudoscientific field of study which later becomes a science (e.g. astrology becoming astronomy and alchemy becoming chemistry).

A theory, methodology, or practice that is considered to be without scientific foundation.

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.

Any body of knowledge that purports to be scientific or to be supported by science but which fails to comply with the scientific method.

Fictitious science as portrayed in science fiction.

An activity resembling science but based on fallacious assumptions