It is possible for us to know what has been achieved in the past, but it is not possible for us to change it. And it is possible for us to change the future, but it is not possible for us to know what will be achieved in it.

The past can only be known, not changed. The future can only be changed, not known.

Alone we cannot build such a social network, or find lasting solutions, but together we can do this.

But we can halt and reverse that trend.

But sometimes we cannot wait for proof.

But we cannot afford to give up hope.

But we can, and must, improve our focus and the effectiveness of our actions.

These are just a few examples far more can be done.

But how should we set about preventing an arms race in outer space?

However, there is something we can do.

But, having said that, we cannot allow the international community to avoid its responsibilities.

But how should we honor Feynman?

But we can change all those things I mentioned.

But I do agree with him about this. We can survive, and we can fail to survive.

The dots are there, but it is hard to see how to connect them.

However, in the context of the present meeting of the First Committee, we are unable to consider their proposals positively.

These structural impediments cannot be removed. But they can be partly overcome with intensive training in Cambodian and international law and complex investigative techniques.

But the danger of a fundamental disintegration has increased over time, and today such an outcome cannot be excluded.

But perhaps there is a deeper level on which we can see some connections between Thatcherism and the crisis.

But we also cannot forget our link with this House, which offered us prompt cooperation.

On another level, however, his appointment can be seen as part of a broader generational shift.

But one thing already can be said for certain the basic distribution of power within Egyptian society has not changed.

So what do we do about this? We can begin with the children.

But we can also celebrate and support and reward the people trying to use cognitive surplus to create civic value.

OK, so what can we learn? These robots are of course not very useful in themselves, but they might teach us something about how we can build better robots, and perhaps how humans, animals, create self models and learn.

We can deliver it this evening.

Yet, even as we address new threats, we should not, and we cannot, ignore the legacy of festering problems left by the past.

We can and must do better, not just in time for her granddaughters and my daughters, but in time for you.

How can we accept this?

Thus, we cannot accept it.

We cannot afford to fail.

If at all possible, we really would like to use smart biomaterials that we can just take off the shelf and regenerate your organs.

Unfortunately, we can't give back that warmth that Anton gave to us. But we can remember him by defending the principles he defended and by following his example by supporting friends, sharing knowledge, and maintaining optimism and sanity.

We think we can throw money at the problem or throw technology at the problem we can undo and unfriend And the problem is that there are certain things that happen in life that we desperately want to change and we cannot.

In potentially uncertain, dangerous and risky environment we need to know very well who we can and who we cannot trust and in which circumstances we can do what.

We can pull out his secrets, and we see that it has a lot to do with candidates, Hillary, presidential, Barack Obama.

We can't fix every problem, but the ones we can, I want to argue, we must.

So, now you can say, all right, why isn't DNA origami the end of the story?

But actually, we have a lot to learn from them, because they're a very egalitarian society and they're a very empathetic society.

What we can do is help the people of the Sudan turn a historic page and enjoy a much, much better future.

But how can we aspire to such a status when we cannot take up lesser challenges within the United Nations because of our resource constraints?

Great. Excellent. That should get us going. All right.

We cannot forget that link.

We cannot prove that a wave of environmental innovation will have a similar effect, but the studies of the parts make such an outcome highly plausible.

We can all make a decision to come together and pick up the balls and run with the balls that governments have dropped.