He soon felt that the fulfillment of his desires gave him only one grain of the mountain of happiness he had expected. This fulfillment showed him the eternal error men make in imagining that their happiness depends on the realization of their desires.
To let them share in the highest offices is to take a risk; inevitably, their unjust standards will cause them to commit injustice, and their lack of judgement will lead them into error. On the other hand there is a risk in not giving them a share, and in their non participation, for when there are many who have no property and no honours they inevitably constitute a huge hostile element in the state. But it can still remain open to them to participate in deliberating and judging.
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.
The cure of the part should not be attempted without treatment of the whole. No attempt should be made to cure the body without the soul. Let no one persuade you to cure the head until he has first given you his soul to be cured, for this is the great error of our day, that physicians first separate the soul from the body.
Indeed the reasoned criticism of a prevailing belief is a service to the proponents of that belief; if they are incapable of defending it, they are well advised to abandon it. This self-questioning and error-correcting aspect of the scientific method is its most striking property.
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.
There is no more evil thing in this world than race prejudice, none at all. [...] It justifies and holds together more baseness, cruelty, and abomination than any other sort of error in the world.
In [chess], where the pieces have different and "bizarre" motions, with various and variable values, what is only complex, is mistaken (a not unusual error) for what is profound
It is too often believed that a person in his progress towards perfection passes from error to truth; that when he passes on from one thought to another, he must necessarily reject the first. But no error can lead to truth. The soul passing through its different stages goes from truth to truth, and each stage is true; it goes from lower truth to higher truth.
It is not to everyone's taste that truth should be pronounced pleasant. But at least let no one believe that error becomes truth when it is pronounced unpleasant.
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.
The only thing that one really knows about human nature is that it changes. Change is the one quality we can predicate of it. The systems that fail are those that rely on the permanency of human nature, and not on its growth and development. The error of Louis XIV was that he thought human nature would always be the same. The result of his error was the French Revolution. It was an admirable result.