There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know. Donald Rumsfeld
There are two great unknown forces today, electricity and woman, but men can reckon much better on electricity than they can on woman. Josephine K. Henry
There are unknown forces in nature; when we give ourselves wholly to her, without reserve, she lends them to us; she shows us these forms, which our watching eyes do not see, which our intelligence does not understand or suspect. Auguste Rodin
There came to port last Sunday night the queerest little craft, without an inch of rigging on; I looked and looked - and laughed. It seemed so curious that she should cross the unknown water, and moor herself within my room - my daughter! O my daughter! George Washington Cable
Therefore I would not have it unknown to Your Holiness, the the only thing which induced me to look for another way of reckoning the movements of the heavenly bodies was that I knew that mathematicians by no means agree in their investigation thereof. Nicolaus Copernicus
Very few beings really seek knowledge in this world. Mortal or immortal, few really ASK. On the contrary, they try to wring from the unknown the answers they have already shaped in their own minds. Anne Rice
Was he an animal if music could captivate him so? It seemed to him that he was being shown the way to the unknown nourishment he had been yearning for.
We have an unknown distance yet to run, an unknown river to explore. What falls there are, we know not; what rocks beset the channel, we know not; what walls ride over the river, we know not. Ah, well! we may conjecture many things. John Wesley Powell
We must expect the discovery of many as yet unknown elements-for example, elements analogous to aluminum and silicon- whose atomic weight would be between 65 and 75. Dmitri Mendeleev
