أن ما يعزز عقول البشر ويوسعها هو التأمل الحر والجريء في أرفع المواضيع وأسماها - John Stuart Mill

First, if any opinion is compelled to silence, that opinion may, for aught we can certainly know, be true. To deny this is to assume our own infallibility. Secondly, though the silenced opinion be an error, it may, and very commonly does, contain a portion of the truth; and since the general or prevailing opinion on any subject is rarely or never the whole truth, it is only by the collision of adverse opinions that the remainder of the truth has any chance of being supplied.

The greater part of the world has, properly speaking, no history, because the despotism of Custom is complete. This is the case over the whole East. Custom is there, in all things, the final appeal; justice and right mean conformity to custom; the argument of custom no one, unless some tyrant intoxicated with power, thinks of resisting. And we see the result. Those nations must once have had originality; they did not start out of the ground populous, lettered, and versed in many of the arts of life; they made themselves all this, and were then the greatest and most powerful nations in the world. What are they now? The subjects or dependants of tribes whose forefathers wandered in the forests when theirs had magnificent palaces and gorgeous temples, but over whom custom exercised only a divided rule with liberty and progress.

There are many truths of which the full meaning cannot be realised, until personal experience has brought it home