Although textbooks (and professors) like to make definite statements indicating that they know what they are talking about, there is in fact a great deal of uncertainty and ambiguity in the world. ...we will not evade this question but rather explore (overexplore?) it. ...great progress is often made when what was long believed to be true is now seen to be perhaps not the whole truth. Thus the text often uses words... to cause you to think about the uncertainess and even the arbitrariness of much of our current conventions and definitions, to ponder about your acceptance of them.

Although our intellect always longs for clarity and certainty, our nature often finds uncertainty fascinating.

The fear of uncertainty is our basic trouble. Uncertainty is the very nature of meaning and the very nature of being, for meaning is always context-dependent. We do not know the context that might come, and this is why we can never be certain that our meanings will be correct and give us security. So if you cannot live with this fact of uncertainty, some distortion is taking place already.

The quest for certainty blocks the search for meaning,' argued the social psychologist Erich Fromm. 'Uncertainty is the very condition to impel man to unfold his powers.' Uncertainty is where things happen. It is where the opportunities – for success, for happiness, for really living – are waiting.

There are some things that you know to be true, and others that you know to be false; yet, despite this extensive knowledge that you have, there remain many things whose truth or falsity is not known to you. We say that you are uncertain about them. You are uncertain, to varying degrees, about everything in the future; much of the past is hidden from you; and there is a lot of the present about which you do not have full information. Uncertainty is everywhere and you cannot escape from it.

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.

The quest for certainty blocks the search for meaning. Uncertainty is the very condition to impel man to unfold his powers.

Ian pretended that not knowing what to do was the hard part when, somewhere inside, I think he knew that making a choice about something is when the real uncertainty begins. The more terrifying uncertainty is wanting something but not knowing how to get it. It is working toward something even though there is no sure thing. When we make choices, we open ourselves up to hard work and failure and heartbreak, so sometimes it feels easier not to know, not to choose, and not to do.

Instead of striving for certainty, we should be in constant search of doubt: doubt about our own beliefs, doubt about our own feelings, doubt about what the future may hold for us unless we get out there and create it for ourselves. Instead of looking to be right all the time, we should be looking for how we’re wrong all the time. Because we are.

Ian pretended that not knowing what to do was the hard part when, somewhere inside, I think he knew that making a choice about something is when the real uncertainty begins. The more terrifying uncertainty is wanting something and not knowing how to get it. It is working toward something even though there is no sure thing. When we make choices, we open ourselves up to hard work and failure and heartbreak, so sometimes it feels easier not to know, not to choose, and not to do.

Uncertainty removes our judgments of others; it preempts the unnecessary stereotyping and biases that we otherwise feel when we see somebody on TV, in the office, or on the street. Uncertainty also relieves us of our judgment of ourselves. 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 means that we do not have a complete description of the world which we fully believe to be true.

Until the last sentence of writing it is always uncertainty

When you're writing you're trying to find out something which you don't know.