It is possible in medicine, even when you intend to do good, to do harm instead. That is why science thrives on actively encouraging criticism rather than stifling it.

Much as we might wish to believe otherwise, universal love and the welfare of the species as a whole are concepts which simply do not make evolutionary sense.

Do not indoctrinate your children. Teach them how to think for themselves, how to evaluate evidence, and how to disagree with you.

Faith is belief without evidence and reason; coincidentally that's also the definition of delusion.

Evolution is just a theory? Well, so is gravity and I don't see you jumping out of buildings.

Such delusions of grandeur to think that a God with a hundred billion galaxies on his mind would give a tuppenny damn who you sleep with, or indeed whether you believe in him.

The less you think, the more you believe.

How thoughtful of God to arrange matters so that, wherever you happen to be born, the local religion always turns out to be the true one.

The universe we observe has precisely the properties we should expect if there is, at bottom, no design, no purpose, no evil, no good, nothing but blind, pitiless indifference.

Science is the poetry of reality.

The theory of evolution by cumulative natural selection is the only theory we know of that is in principle capable of explaining the existence of organized complexity.

Life is love.Love is divine.Divine is God.

You wrote in a poem, “I love your body, ” as if love was for you embodied in the senses, and yet more than the senses together, an enveloping sense itself sensuous, as if all the body made sense.

Perhaps it’s my natural pessimism, but it seems that an awfully large part of travel these days is to see things while you still can.

The rage for railroads is so great that many will be laid in parts where they will not pay.

What we call love is the desire to awaken and to keep awake in another's body heart and mind the responsibility of flattering in our place the self of which we are not very certain.

We cannot get to where we dream of being tomorrow unless we change our thinking today.

Mend the part of the world that is within your reach.

The cutting of primeval forest and other disasters, fueled by the demands of growing human populations, are the overriding threat to biological diversity everywhere.

You should always live within your income, even if you have to borrow to do so.

All loose things seem to drift down to the sea, and so did I.