David Hume

Be a philosopher, but amid all your philosophy be still a man - the famous philosopher, David Hume

Patrick Henry

Gentlemen may cry, Peace, Peace — but there is no peace. The war is actually begun! The next gale that sweeps from the north will bring to our ears the clash of resounding arms! Our brethren are already in the field! Why stand we here idle? What is it that gentlemen wish? What would they have? Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery? Forbid it, Almighty God! I know not what course others may take; but as for me, give me liberty or give me death! – Patrick Henry, March 23, 1775

Santayana

Art, like life, should be free, since both are experimental. - Philosopher, poet, literary and cultural critic, George Santayana

He is perhaps best known for his oft-quoted

"Those who cannot learn from history are doomed to repeat it," from Reason in Common Sense, the first volume of his The Life of Reason.

Also like this one:

"To have imagination and taste, to love the best, to be carried by the contemplation of nature to a vivid faith in the ideal, all this is more, a great deal more, than any science can hope to be. The poets and philosophers who express this aesthetic experience and stimulate the same function in us by their example, do a greater service to mankind and deserve higher honor than the discoveries of historical truths." - from The Sense of Beauty

More quotes from him here.