The spirit of improvement is ...

The spirit of improvement is not always a spirit of liberty, for it may aim at forcing improvements on an unwilling people.
The spirit of improvement is not always a spirit of liberty, for it may aim at forcing improvements on an unwilling people.

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All the great things are simple, and many can be expressed in a single word: freedom, justice, honor, duty, mercy, hope.
I know but one freedom and that is the freedom of the mind.
 Antoine de Saint-Exupéry
Freedom is not worth having if it does not connote freedom to err.
The amount of happiness that you have depends on the amount of freedom you have in your heart.
 Thích Nhất Hạnh
Without freedom of thought, there can be no such thing as wisdom - and no such thing as public liberty without freedom of speech.

Quotes from the same author

Accordingly, France Had Voltaire, and his school of negative thinkers, and England (or rather Scotland) had the profoundest negative thinker on record, David Hume: a man, the peculiarities of whose mind qualified him to detect failure of proof, and want of logical consistency, at a depth which French skeptics, with their comparatively feeble powers of analysis and abstractions stop far short of, and which German subtlety alone could thoroughly appreciate, or hope to rival.
What citizens of a free country would listen to any offers of good and skillful administration in return for the abdication of freedom?
Men and governments must act to the best of their ability. There is no such thing as absolute certainty but there is assurance sufficient for the purposes of human life.
When one's ideas are not challenged, one's ability to defend them weakens.
One person with a belief is equal to ninety-nine who have only interests.