If we have an atom that is in an excited state and so is going to emit a photon, we cannot say when it will emit the photon. It has a certain amplitude to emit the photon at any time, and we can predict only a probability for emission; we cannot predict the future exactly.

Some people feel affronted when something they thought to be true doesn’t happen. If that’s the case, then your sense of risk is much higher, and that leads to risk aversion. You need to be able to be comfortable in uncertainty.

The probability that we may fail in the struggle ought not to deter us from the support of a cause we believe to be just.

If we must not act save on a certainty, we ought not to act on religion, for it is not certain. But how many things we do on an uncertainty, sea voyages, battles!

Scientific views end in awe and mystery, lost at the edge in uncertainty, but they appear to be so deep and so impressive that the theory that it is all arranged as a stage for God to watch man’s struggle for good and evil seems inadequate.

If a man will begin with certainties, he shall end in doubts, but if he will content to begin with doubts, he shall end in certainties.

I used to get the feeling, and sometimes I still get it, that sometimes I was fooling somebody; I don’t know who or what, maybe myself.

We fear that this moment will end, that we won’t get what we need, that we will lose what we love, or that we will not be safe. Often, our biggest fear is the knowledge that one day our bodies will cease functioning. So even when we are surrounded by all the conditions for happiness, our joy is not complete.

In this quest to seek and find God in all things, there is still an area of uncertainty. There must be. If a person says that he met God with total certainty and is not touched by a margin of uncertainty, then this is not good.

Our lifelong certainties about the world can be demolished in a single second.

If you only do things where you know the answer in advance, your company goes away.

It is not scientifically possible to accurately predict the outcome of an action. To suggest otherwise runs contrary to historical experience and the nature of war.

I don’t know what can be so dangerous about giving people hope.

We know what we are, but know not what we may be.

I don’t like to commit myself about heaven and hell – you see, I have friends in both places.

The more I see the less I know for sure.

I don’t know what ‚normal‘ means, anyway.

I think that when we know that we actually do live in uncertainty, then we ought to admit it; it is of great value to realize that we do not know the answers to different questions. This attitude of mind – this attitude of uncertainty – is vital to the scientist, and it is this attitude of mind which the student must first acquire.

It is only by risking our persons from one hour to another that we live at all. And often enough our faith beforehand in an uncertified result is the only thing that makes the result come true.

It is in the admission of ignorance and the admission of uncertainty that there is a hope for the continuous motion of human beings in some direction that doesn’t get confined, permanently blocked, as it has so many times before in various periods in the history of man.

This is the first age that’s ever paid much attention to the future, which is a little ironic since we may not have one.

Our need for certainty in an endeavor as uncertain as raising children makes explicit ‚how-to-parent‘ strategies both seductive and dangerous.

The true and the approximately true are apprehended by the same faculty; it may also be noted that men have a sufficient natural instinct for what is true, and usually do arrive at the truth. Hence the man who makes a good guess at truth is likely to make a good guess at probabilities.

Would you bet your paycheck on a weather forecast for tomorrow? If not, then why should this country bet billions on global warming predictions that have even less foundation?

U2’s best work has always been when we didn’t know what we’re doing.

The uncertainty of parenting can bring up feelings in us that range from frustration to terror.

To be absolutely certain about something, one must know everything or nothing about it.

You can’t learn in school what the world is going to do next year.

I always wonder when it was that I was embraced.

As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality.

I’m very careful about saying who would and wouldn’t go to heaven. I don’t know.

We are afraid to care too much, for fear that the other person does not care at all.

A hustler has to deal with danger and risk. It’s part of the game. You cannot control it all, nor would you want to. Chaos, unknown factors are not something to be anxious about.

Nothing in life is promised except death.

Truth is so obscure in these times, and falsehood so established, that, unless we love the truth, we cannot know it.

Younger people have greatest fears. Why is that? Because they don’t know the plot. They don’t know their own individual plot… they don’t know what’s going to happen to them.

I’m not a fortune-teller.

Change is always tough. Even for those who see themselves as agents of change, the process of starting a new thing can cause times of disorientation, uncertainty and insecurity.

Love and doubt have never been on speaking terms.

A question that sometimes drives me hazy: am I or are the others crazy?

Every possession and every happiness is but lent by chance for an uncertain time, and may therefore be demanded back the next hour.

It’s hard to speculate what tomorrow may bring.

Our problem right now is that we’re so specialized that if the lights go out, there are a huge number of people who are not going to know what to do. But within every dystopia there’s a little utopia.

If there’s one thing that’s certain in business, it’s uncertainty.

Waking up every day and loving someone who may or may not love us back, whose safety we can’t ensure, who may stay in our lives or may leave without a moment’s notice, who may be loyal to the day they die or betray us tomorrow – that’s vulnerability.

I don’t have all the answers.

I would never die for my beliefs because I might be wrong.

Economic medicine that was previously meted out by the cupful has recently been dispensed by the barrel. These once unthinkable dosages will almost certainly bring on unwelcome after-effects. Their precise nature is anyone’s guess, though one likely consequence is an onslaught of inflation.

Doubt is not a pleasant condition, but certainty is absurd.

From the time I was a kid, I always knew something was going to happen to me. Didn’t know exactly what.

You know, people talk about this being an uncertain time. You know, all time is uncertain. I mean, it was uncertain back in – in 2007, we just didn’t know it was uncertain. It was – uncertain on September 10th, 2001. It was uncertain on October 18th, 1987, you just didn’t know it.

I want to marry Arline because I love her – which means I want to take care of her. That is all there is to it. I want to take care of her. I am anxious for the responsibilities and uncertainties of taking care of the girl I love.

It’s no exaggeration to say that the undecideds could go one way or another.

I hate cameras. They are so much more sure than I am about everything.

We think that life develops spontaneously on Earth, so it must be possible for life to develop on suitable planets elsewhere in the universe. But we don’t know the probability that a planet develops life.

When in doubt, don’t.

Vulnerability is basically uncertainty, risk, and emotional exposure.

Things on a very small scale behave like nothing that you have any direct experience about. They do not behave like waves, they do not behave like particles, they do not behave like clouds, or billiard balls, or weights on springs, or like anything that you have ever seen.

Life’s short. Anything could happen, and it usually does, so there is no point in sitting around thinking about all the ifs, ands and buts.

Certain though I am – and ever more certain – that I must press on in life as though Christ awaited me at the term of the universe, at the same time I feel no special assurance of the existence of Christ. Believing is not seeing. As much as anyone, I imagine, I walk in the shadows of faith.

It’s not easy being young. It’s hard to know what to do.