All progress is initiated by challenging current conceptions, and executed by supplanting existing institutions.

The United States has to move very fast to even stand still.

He that is good, will infallibly become better, and he that is bad, will as certainly become worse; for vice, virtue and time are three things that never stand still.

I walk slowly, but I never walk backward.

Progress, under whose feet the grass mourns and the forest turns into paper from which newspaper plants grow, has subordinated the purpose of life to the means of subsistence and turned us into the nuts and bolts for our tools.

The characteristic of scientific progress is our knowing that we did not know.

It is curious to note the old sea-margins of human thought! Each subsiding century reveals some new mystery; we build where monsters used to hide themselves.

All progress means war with society.

Progress is the stride of God.

Progress, far from consisting in change, depends on retentiveness. When change is absolute there remains no being to improve and no direction is set for possible improvement: and when experience is not retained, as among savages, infancy is perpetual.