undemonstrated

By dint of hard work and undemonstrated brilliance, Redl rises to high military and social rank and becomes deputy chief of the army's espionage service.

From Time Magazine Archive

It is entirely undemonstrated; it may never be proved.

From "Cosmos" by Carl Sagan

For one is an ascent from sensibles to the first intelligibles; a second is an ascent through things demonstrated and subdemonstrated, to undemonstrated and immediate propositions; and a third proceeds from hypothesis to unhypothetical principles.

From Introduction to the Philosophy and Writings of Plato by Thomas Taylor

It is a necessity in science, but intangible, undemonstrated, unknown, and wholly theoretical.

From Etidorhpa or the End of Earth. The Strange History of a Mysterious Being and The Account of a Remarkable Journey by John Uri Lloyd

We are already in a position to say with almost complete freedom from uncertainty what undefined simple notions and undemonstrated postulates we have to employ in the science and to express these ultimates without ambiguity.

From Recent Developments in European Thought by Various