George Berkeley

Others indeed may talk, and write, and fight about liberty, and make an outward pretence to it but the free-thinker alone is truly free.

To be is to be perceived (Esse est percipi)." Or, "If a tree falls in the forest and no one is there to hear it, does it make a sound?

Truth is the cry of all, but the game of few.

All the choir of heaven and furniture of earth - in a word, all those bodies which compose the frame of the world - have not any subsistence without a mind.

The same principles which at first view lead to skepticism, pursued to a certain point, bring men back to common sense.

Many things, for aught I know, may exist, whereof neither I nor any other man hath or can have any idea or notion whatsoever.

A ray of imagination or of wisdom may enlighten the universe, and glow into remotest centuries.

We have first raised a dust and then complain we cannot see.

That neither our thoughts, nor passions, nor ideas formed by the imagination, exist without the mind, is what every body will allow.

A mind at liberty to reflect on its own observations, if it produce nothing useful to the world, seldom fails of entertainment to itself.

Doth the Reality of sensible things consist in being perceived? or, is it something distinct from their being perceived, and that bears no relation to the mind?

He who says there is no such thing as an honest man, you may be sure is himself a knave.

Few men think, yet all will have opinions.