Scientists often talk of parsimony (as in "the simplest explanation is probably correct," also known as Occam's razor), but we should not get seduced by the apparent elegance of argument from parsimony; this line of reasoning has failed in the past at least as many times as it has succeeded.

It turns out that dopamine is a chemical on double duty in the brain. Along with its role in motor commands, it also serves as the main messenger in the reward systems, guiding a person toward food, drink, mates, and all things useful for survival. Because of its role in the reward system, imbalances in dopamine can trigger gambling, overeating, and drug addiction - behaviors that result from a reward system gone awry.

We are nothing but the product of billions of years of molecules coming together and ratcheting up through natural selection, we are composed only of highways of fluids and chemicals sliding along roadways within billions of dancing cells, trillions of synaptic conversations hum in parallel, this vast egglike fabric of micron-thin circuitry runs algorithms undreamt of in modern science, and these neural programs give rise to our decision making, loves, desires, fears, and aspirations. That understanding would be a numinous experience, better than anything ever proposed in anyone's holy text.

None of the individual metal hunks of an airplane have the property of flight, but when they are attached together in the right way, the result takes to the air. A thin metal bar won't do you much good if you're trying to control a jaguar, but several of them in parallel have the property of containment. The concept of emergent properties means that something new can be introduced that is not inherent in any of the parts.

There are three deaths. The first is when the body ceases to function. The second is when the body is consigned to the grave. The third is that moment, sometime in the future, when your name is spoken for the last time.

We spend our lives on a thin slice between the unimaginably small scales of the atoms that compose us and the infinitely large scales of galaxies.

If an epileptic seizure is focused in a particular sweet spot in the temporal lobe, a person won´t have motor seizures, but instead something more subtle. The effect is something like a cognitive seizure, marked by changes of personality, hyperreligiosity (an obsession with religion and feelings of religious certainity), hypergraphia (extensive writing on a subject, usually about religion), the false sense of an external presence, and, often, the hearing voices that are attributed to a god. Some fraction of history´s prophets, martyrs, and leaders appear to have had temporal lobe epilepsy.