Evil, by definition, is that which endangers the good, and the good is what we perceive as a value.

It is a good morning exercise for a research scientist to discard a pet hypothesis every day before breakfast. It keeps him young.

Historians will have to face the fact that natural selection determined the evolution of cultures in the same manner as it did that of species.

Every man gets a narrower and narrower field of knowledge in which he must be an expert in order to compete with other people. The specialist knows more and more about less and less and finally knows everything about nothing.

I have found the missing link between the higher ape and civilized man; it is we.

We do not take humor seriously enough.

Evil, by definition, is that which endangers the good, and the good is what we perceive as a value.

We had better dispense with the personification of evil, because it leads, all too easily, to the most dangerous kind of war: religious war.

Most of the vices and mortal sins condemned today correspond to inclinations that were purely adaptive or at least harmless in primitive man.

Truth in science can be defined as the working hypothesis best suited to open the way to the next better one.

I believe that present day civilized man suffers from insufficient discharge of his aggressive drive.

Barking dogs occasionally bite, but laughing men hardly ever shoot.

The bond with a true dog is as lasting as the ties of this earth will ever be.

'I don't need brains,' says the billionaire contemptuously. 'I'm brainy enough myself!' The broker cries out in desperation, 'What, in heaven's name, do you want?' 'Goodness,' is the answer.

Ethologists are often accused of drawing false analogies between animal and human behaviour. However, no such thing as a false analogy exists: an analogy can be more or less detailed and, hence, more or less informative.

From a neighbour, I got a one-day-old duckling and found, to my intense joy, that it transferred its following response to my person. At the same time, my interest became irreversibly fixated on water fowl, and I became an expert on their behaviour even as a child.

I consider early childhood events as most essential to a man's scientific and philosophical development.

I grew up in the large house and the larger garden of my parents in Altenberg. They were supremely tolerant of my inordinate love for animals.

I owe undying gratitude to my patient parents.

In the course of evolution, it constantly happens that, independently of each other, two different forms of life take similar, parallel paths in adapting themselves to the same external circumstances.

Practically all animals which move fast in a homogeneous medium have found means of giving their body a streamlined shape, thereby reducing friction to a minimum.

The father-mother family with two children isolated in a city flat is already insufficient.

There is indeed the possibility that the evolutionary process has, in gray antiquity, bred into us an excess of aggression.

When I was about ten, I discovered evolution by reading a book by Wilhelm Boelsche and seeing a picture of Archaeopteryx.

Whenever we find, in two forms of life that are unrelated to each other, a similarity of form or of behaviour patterns which relates to more than a few minor details, we assume it to be caused by parallel adaptation to the same life-preserving function.

The human mind in taking us down the path of technocracy has become the adversary of life itself and collaterally the adversary of the human soul.

Man has been driven out of the paradise in which he could trust his instincts.

The cat is a wild animal that inhabits the homes of humans.

The bond with a dog is as lasting as the ties of this earth can ever be

Boldness and decision command, often even in evil, the respect and concurrence of mankind.

For those whose wit becomes the mother of villainy, those it educates to be evil in all things.

Words - so innocent and powerless as they are, as standing in a dictionary, how potent for good and evil they become in the hands of one who knows how to combine them.

Some things must be good in themselves, else there could be no measure whereby to lay out good and evil.

Destroy the seed of evil, or it will grow up to your ruin.

Once to every person and nation come the moment to decide. In the conflict of truth with falsehood, for the good or evil side.

Into every soul, however purged and fenced, evil appears to have as much freedom of entrance as God Himself.

What I have learned from my work up to now, is to try to be open, but also protect myself by not letting the good and the evil get too much importance.

Mankind is not likely to salvage civilization unless he can evolve a system of good and evil which is independent of heaven and hell.

One who is injured ought not to return the injury, for on no account can it be right to do an injustice; and it is not right to return an injury, or to do evil to any man, however much we have suffered from him.

The 20th century taught us how far unbridled evil can and will go when the world fails to confront it. It is time that we heed the lessons of the 20th century and stand up to these murderers. It is time that we end genocide in the 21st century.

Every war results from the struggle for markets and spheres of influence, and every war is sold to the public by professional liars and totally sincere religious maniacs, as a Holy Crusade to save God and Goodness from Satan and Evil.

A great book is like great evil.

May the forces of evil become confused on the way to your house.

Be assured those will be thy worst enemies, not to whom thou hast done evil, but who have done evil to thee. And those will be thy best friends, not to whom thou hast done good, but who have done good to thee.

Hatred is gained as much by good works as by evil.

Neither gods nor men can foresee when an evil deed will bear its fruit.

Wisdom is the knowledge of good and evil, not the strength to choose between the two.

I am in politics because of the conflict between good and evil, and I believe that in the end good will triumph.

Every Christian will allow that sin is an evil, and that it is our duty not to commit sin.