For knowing is spoken of in three ways: it may be either universal knowledge or knowledge proper to the matter in hand or actualising such knowledge; consequently three kinds of error also are possible.
To free a man from error is to give, not to take away. Knowledge that a thing is false is a truth. Error always does harm; sooner or later it will bring mischief to the man who harbors it.
The mind moves by instincts, associations and premonitions and not by fixed dates or completed processes. Action and reaction will occur simultaneously: or the cause actually be found after the effect. Errors will be resisted before they have been properly promulgated: notions will be first defined long after they are dead.
When we look at the matter from another point of view, great caution would seem to be required. For the habit of lightly changing the laws is an evil, and, when the advantage is small, some errors both of lawgivers and rulers had better be left; the citizen will not gain so much by making the change as he will lose by the habit of disobedience.
For truth is strong next to the Almighty. She needs no policies or stratagems or licensings to make her victorious. These are the shifts and the defences that error uses against her power.
Eratosthenes's only tools were sticks, eyes, feet, and brains; plus a zest for experiment. With those tools he correctly deduced the circumference of the Earth, to high precision, with an error of only a few percent. That's pretty good figuring for 2200 years ago.
We early arrive at the great discovery that there is one mind common to all individual men: that what is individual is less than what is universalthat error, vice and disease have their seat in the superficial or individual nature.
We are prodding, challenging, seeking contradictions or small, persistent residual errors, proposing alternative explanations, encouraging heresy. We give our highest rewards to those who convincingly disprove established beliefs.
What is toleration? It is the prerogative of humanity. We are all steeped in weaknesses and errors: Let us forgive one another's follies, it is the first law of nature.
Those wretches who never have experienced the sweets of wisdom and virtue, but spend all their time in revels and debauches, sink downward day after day, and make their whole life one continued series of errors.