Nothing is more dangerous to reason than the flights of the imagination and nothing has been the occasion of more mistakes among philosophers. Men of bright fancies may in this respect be compared to those angels whom the scripture represents as covering their eyes with their wings.
A Treatise of Human Nature by David Hume, Book 1, Section 4, p.225
Philosophy makes progress not by becoming more rigorous but by becoming more imaginative.
Introduction to Truth and Progress: Philosophical Papers by Richard Rorty, Volume 3, 1998.
The conception of the necessary unit of all that is resolves itself into the poverty of the imagination, and a freer logic emancipates us from the straitwaistcoated benevolent institution, which idealism palms off as the totality of being.
Our Knowledge of the External World by Bertrand Russell
The true function of logic,... as applied to matters of experience,... is analytic rather than constructive; taken a priori, it shows the possibility of hitherto unsuspected alternatives more often than the impossibility of alternatives which seemed prima facie possible. Thus, while it liberates imagination as to what the world may be, it refuses to legislate as to what the world is.
Our Knowledge of the External World by Bertrand Russell
Science does not know its debt to imagination.
Poetry and Imagination by Ralph Waldo Emerson, 1872.
Cowardice, as distinguished from panic, is almost always simply a lack of ability to suspend the functioning of the imagination.
Introduction to Men at War by Ernest Hemingway, 1942.
There is no life I knowthat compares to pure imaginationLiving there you'll be freeif you truly wish to be
Pure Imagination|Pure Imagination by Gene Wilder, 1971.
Impossibility is only the figment of an insufficient imagination.
The Song Of Sin by Phil Duncan, 1998.