There are many other (besides testosterone) behaviour-eliciting hormones fundamental for humen well-being, including estrogen and progesterone in females. The fact that complex behavioural patterns can be triggered by a tiny concentration of moleculas coursing through the bloodstream, and that different animals of the same species generate different amounts of these hormones, is something worth thinking about when it's time to judge such matters as free will, individual responsibility, and law and order.

A galaxy is composed of gas and dust and stars - billions upon billions of stars. Every star may be a sun to someone.

Who are we, if not measured by our impact on others? That’s who we are! We’re not who we say we are, we’re not who we want to be - we are the sum of the influence and impact that we have, in our lives, on others.

Books break the shackles of time, proof that humans can work magic.

If we can't think for ourselves, if we're unwilling to question authority, then we're just putty in the hands of those in power. But if the citizens are educated and form their own opinions, then those in power work for us. In every country, we should be teaching our children the scientific method and the reasons for a Bill of Rights. With it comes a certain decency, humility and community spirit. In the demon-haunted world that we inhabit by virtue of being human, this may be all that stands between us and the enveloping darkness.

Billions and billions.

But down deep, at the molecular heart of life we're essentially identical to trees.