There is no scientific reason to think that we, even with space travel, are going to survive as a species for ever, certainly not by biting off the hand that feeds us, which is exactly what we are doing.

Sports exact too harsh a toll on our beautiful women. Like engendered species, they should be protected, and instead, we exploit them and demand they fly too close to the sun for our amusement. We send them into the arena for an exhausting three-setter, an 18-hole playoff, a 200th lap. The burnout factor is insurmountable.

If we confound and break up the proposed unfolding the world impresses upon us, we can give ourselves the space to consider what we want to be as a species.

Evolution doesn't care whether you believe in it or not, no more than gravity does. I want to rekindle excitement over what we've achieved as a species with the space program. We can't afford to regress back to the days of superstition.

My childhood dreams were focused on being part of the effort to make humanity a multiplanetary species.

Wildlife crime goes well beyond just a threat to endangered species but also has impacts on our society, economy and security. It undermines efforts to uphold the rule of law, acts as an agent for corruption, creates a barrier to development and fuels global instability.

Science, already oppressive with its shocking revelations, will perhaps be the ultimate exterminator of our human species - if separate species we be - for its reserve of unguessed horrors could never be borne by mortal brains if loosed upon the world.

Transhumanism is the ethics and science of using things like biological and genetic engineering to transform our bodies and make us a more powerful species.

The mineral world is a much more supple and mobile world than could be imagined by the science of the ancients. Vaguely analogous to the metamorphoses of living creatures, there occurs in the most solid rocks, as we now know, perpetual transformation of a mineral species.

On the ordinary view of each species having been independently created, we gain no scientific explanation.

About 15,000 years ago, humans colonised America, wiping out in the process about 75% of its large mammals. Numerous other species disappeared from Africa, from Eurasia, and from the myriad islands around their coasts. The archaeological record of country after country tells the same sad story.

I am not very proud of being an human being; in fact, I distinctly dislike the species in many ways. I can readily conceive of beings vastly superior in every respect.

Is it not a species of blasphemy to call the New Testament revealed religion, when we see in it such contradictions and absurdities.

If we just wanted positive emotions, our species would have died out a long time ago.

If epic poetry is a definite species, the sagas do not fall within it.

Animal rights can be as extreme as not riding a horse, or not wearing leather, not having a pet at all. Animal welfare advocates are preventing the suffering of animals. And then there's conservation and species conservation and what conservation biologists do.

A dog is a vehicle, you know; a dog is a window to Mother Nature, and that's the closest species we have.

To many people, 'biodiversity' is almost synonymous with the word 'nature,' and 'nature' brings to mind steamy forests and the big creatures that dwell there. Fair enough. But biodiversity is much more than that, for it encompasses not only the diversity of species, but also the diversity within species.

A human being would certainly not grow to be seventy or eighty years old if this longevity had no meaning for the species. The afternoon of human life must also have a significance of its own and cannot be merely a pitiful appendage to life's morning.

I describe not men, but manners; not an individual, but a species.

There are many ways to make the most of your time on the planet, and propagation of the species is just one of them. If you're convinced that it's the key to your happiness, there are routes open to you, whether with the help of modern medical science, marrying into a readymade one, or through fostering and adoption.

The social relations which are the basis of the reproduction of the species are founded upon the continuous union of parents in marriage.

A man reserves his true and deepest love not for the species of woman in whose company he finds himself electrified and enkindled, but for that one in whose company he may feel tenderly drowsy.

As a species, we can at times be dimwitted and cruel. But we're also capable of learning.