that in order to progress we must recognize our ignorance and leave room for doubt.

To admit uncertainty is to admit to weakness, to powerlessness, and to believe in yourself despite both. It is a frailty, but in this frailty there is a strength: the conviction to live in your own mind, and not in someone else’s.

History is littered with good ideas taken too far, which are indistinguishable from bad ideas. The wisdom in having room for error is acknowledging that uncertainty, randomness, and chance — “unknowns” — are an ever-present part of life. The only way to deal with them is by increasing the gap between what you think will happen and what can happen while still leaving you capable of fighting another day.

Ah, but ignorance is better. At least then there's hope.

Whatever the progress of human knowledge, there will always be room for ignorance, hence for chance and probability.

Hope locates itself in the premises that we don’t know what will happen and that in the spaciousness of uncertainty is room to act. When you recognize uncertainty, you recognize that you may be able to influence the outcomes–you alone or you in concert with a few dozen or several million others. Hope is an embrace of the unknown and knowable, a alternative to the certainty of both optimists and pessimists. Optimists think it will all be fine without our involvement; pessimists take the opposite position; both excuse themselves from acting. It’s the belief that what we do matters even though how and when it may matter, who and what it may impact, are not things we can know beforehand. We may not, in fact, know them afterward either, but they matter all the same, and history is full of people whose influence was most powerful after they were gone.

I am not disposed to bewail the limitations imposed by human ignorance. On the contrary, I feel ignorance is a healthful stimulant; and my enforced conviction that neither I nor anyone can possibly lay down beforehand what does not exist in the universe, or even what is not going on all round us everyday of our lives, leaves me with a cheerful hope that something very new and very arresting may turn up anywhere at any minute. … I shall try to utilize this temper of mind today by clearing away, so far as I can, certain presuppositions, on one side or on the other, which seem to me to depend upon a too hasty assumption that we know more about the universe than as yet we really can know.

If there is something that opens horizons, it is precisely ignorance.

Admission of ignorance is often the first step in our education.

We need to accept our ignorance and say ‘I don’t know’ more often.

It takes a lot of courage to fight biases and oppressive regimes, but it takes even greater courage to admit ignorance and venture into the unknown. Secular education teaches us that if we don’t know something, we shouldn’t be afraid of acknowledging our ignorance and looking for new evidence. Even if we think we know something, we shouldn’t be afraid of doubting our opinions and checking ourselves again. Many people are afraid of the unknown, and want clear-cut answers for every question. Fear of the unknown can paralyse us more than any tyrant. People throughout history worried that unless we put all our faith in some set of absolute answers, human society will crumble. In fact, modern history has demonstrated that a society of courageous people willing to admit ignorance and raise difficult questions is usually not just more prosperous but also more peaceful than societies in which everyone must unquestioningly accept a single answer. People afraid of losing their truth tend to be more violent than people who are used to looking at the world from several different viewpoints. Questions you cannot answer are usually far better for you than answers you cannot question.

The willingness to consider possibility requires a tolerance of uncertainty.

Uncertainty also relieves us of our judgment of ourselves. Then we don’t know if we’re lovable or not; we don’t know how attractive we are; we don’t know how successful we could potentially become. The only way to achieve these things is to remain uncertain of them and be open to finding them out through experience. Uncertainty is the root of all progress and all growth. As the old adage goes, the man who believes he knows everything learns nothing. We cannot learn anything without first not knowing something.

A temporary evolution of ignorance, a period when our insistence on looking in certain directions leaves us unable to see what is right under our noses, may be the price of progress, an inevitable part of what happens when we try to make sense of the world's complexity.