It is only of life on Earth, however, that one can speak with any certainty. It seems to me that all life on Earth, the sum total of life upon the Earth, has purpose.

We said, there's another second gone, there's another minute and another hour and another day, when, as a matter of fact the second or the minute or the hour was never gone. It was the same one all the time. It had just moved along and we had moved with it.

Time is still the great mystery to us. It is no more than a concept; we don't know if it even exists.

It was a place without a single feature of the space-time matrix that he knew. It was a place where nothing yet had happened - an utter emptiness. There was neither light nor dark: there was nothing here but emptiness.

It would seem to me that by the time a race has achieved deep space capability it would have matured to a point where it would have no thought of dominating another intelligent species.

These are the stories the Dogs tell, when the fires burn high and the wind is from the north.

When I talk of the purpose of life, I am thinking not only of human life, but of all life on Earth and of the life which must exist upon other planets throughout the universe.

Must faith be exactly that, the willingness and ability to believe in the face of a lack of evidence? If one could find the evidence, would then the faith be dead?

Without consciousness and intelligence, the universe would lack meaning.

If the means were available, we could trace our ancestry - yours and mine - back to the first blob of life-like material that came into being on the planet.

If mankind were to continue in other than the present barbarism, a new path must be found, a new civilization based on some other method than technology.

It is only of life on Earth, however, that one can speak with any certainty. It seems to me that all life on Earth, the sum total of life upon the Earth, has purpose.

Could that have been what happened to the human race - a willing perversity that set at naught all human values which had been so hardly won and structured in the light of reason for a span of more than a million years?

Less than an hour before he'd congratulated himself on escaping all the traps of Earth, all the snares of Man. Not knowing that the greatest trap of all, the final and the fatal trap, lay on this present planet.

What do you mean by faith? Is faith enough for Man? Should he be satisfied with faith alone? Is there no way of finding out the truth? Is the attitude of faith, of believing in something for which there can be no more than philosophic proof, the true mark of a Christian?

And time itself? Time was a never-ending medium that stretched into the future and the past - except there was no future and no past, but an infinite number of brackets, extending either way, each bracket enclosing its single phase of the Universe.

My reluctance to use alien invasion is due to the feeling that we are not likely to be invaded and taken over.

It seems to me, thinking of it, that there must be some universal plan which set in motion the orbiting of the electrons about the nucleus and the slower, more majestic orbit of the galaxies about one another to the very edge of space.

Without consciousness and intelligence the universe would lack meaning.

When I tested for Billy Budd, I had that kind of confidence that comes with the certainty that you're not going to get something. I was very rough around the edges.

A liberal knows that the only certainty in this life is change but believes that the change can be directed toward a constructive end.

From this bestial view that the human mind consists of only sense certainty, pleasure and pain, Locke developed an equally bestial theory of the nation. Man originally existed in a State of Nature of complete liberty.

I feel, sometimes, as the renaissance man must have felt in finding new riches at every point and in the certainty that unexplored areas of knowledge and experience await at every turn.

I am certain there is too much certainty in the world.

The only certainty is that nothing is certain.

The Resistance is a moral certainty, not a poetic one. The true poet never uses words in order to punish someone. His judgment belongs to a creative order; it is not formulated as a prophetic scripture.

The areas of consensus shift unbelievably fast; the bubbles of certainty are constantly exploding.

There is no certainty; there is only adventure.

We can say with certainty - or 90% probability - that the new industries that are about to be born will have nothing to do with information.

If you develop the absolute sense of certainty that powerful beliefs provide, then you can get yourself to accomplish virtually anything, including those things that other people are certain are impossible.

I found it peculiar that those who wanted to take military action could - with 100 per cent certainty - know that the weapons existed and turn out to have zero knowledge of where they were.

From principles is derived probability, but truth or certainty is obtained only from facts.

Hope is not the conviction that something will turn out well but the certainty that something makes sense, regardless of how it turns out.

Fundamentalists are panicked by the apparent disintegration of the family, the disappearance of certainty and the decay of morality. Fear leads them to ask, if we cannot trust the Bible, what can we trust?

It is to be feared that those who emigrate to New South Wales, generally anticipate too great facility in their future operations and certainty of success in conducting them; but they should recollect that competency cannot be obtained without labour.

One must verify or expel his doubts, and convert them into the certainty of Yes or NO.

A bird in hand is a certainty. But a bird in the bush may sing.

As a painter today you have to work without that essential platform. But if one does not deceive oneself and accepts this lack of certainty, other things may come into play.

Sooner or later you must move down an unknown road that leads beyond the range of the imagination, and the only certainty is that the trip has to be made.

Dogmatism and skepticism are both, in a sense, absolute philosophies; one is certain of knowing, the other of not knowing. What philosophy should dissipate is certainty, whether of knowledge or ignorance.

The unique and supreme voluptuousness of love lies in the certainty of committing evil. And men and women know from birth that in evil is found all sensual delight.

Science has proof without any certainty. Creationists have certainty without any proof.

Doubt is to certainty as neurosis is to psychosis. The neurotic is in doubt and has fears about persons and things; the psychotic has convictions and makes claims about them. In short, the neurotic has problems, the psychotic has solutions.

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

We regard it as a certainty that the earth, enclosed between poles, is bounded by a spherical surface.

When the human mind exists in the light of reason and no more than reason, we may say with absolute certainty that Man and all that made him will be in that instant gone.

If a man fights his way through his doubts to the conviction that Jesus Christ is Lord, he has attained to a certainty that the man who unthinkingly accepts things can never reach.

To counter the avoidance of intellectual challenge and responsibility, we must reduce the domination of certainty in education.

No great deed is done by falterers who ask for certainty.