In Philosophy of sciences, a protoscience is a new scientific discipline which is at the stage of the formulation and the speculation, and which could see some of its proposals thereafter establishing the bases of a news Science or on the contrary to be rejected.

Examples:

• certain parts of alchemy were kept to become chemistry, whereas others as the transmutation passed in the legend.
• ancient astrology gave rise to astronomy, whereas its part divinatory art became current astrology, generally considered like a Pseudo-science