We have one planet in our solar system that's habitable, and that's the Earth, and space travel can transform things back here for the better. First of all, by just having people go to space and look back on this fragile planet we live on. People have come back transformed and have done fantastic things.

One in 200 stars has habitable Earth-like planets surrounding it - in the galaxy, half a billion stars have Earth-like planets going around them - that's huge, half a billion. So when we look at the night sky, it makes sense that someone is looking back at us.

Here on Earth, we've found organisms that thrive in environmental conditions we would have once thought uninhabitable. The presence of these extremophiles suggests that life could potentially take hold on worlds other than our own.

This world, in which reason is more and more at home, is not habitable. It is hard and cold like those depots in which are piled up goods that cannot satisfy: neither clothe those who are naked, nor feed those who are hungry; it is as impersonal as factory hangars and industrial cities in which manufactured things remain abstract, true with statistical truth and borne on the anonymous circuit of the economy, resulting from skilful planning decisions which cannot prevent, but prepare disasters. There it is, the mind in its masculine essence, living on the outside, exposed to the violent, blinding sun, to the trade winds that beat against it and beat it down, on a land without folds, rootless, solitary and wandering and thus already alienated by the very things which it caused to be produced and which remain untameable and hostile.