The first lesson about trusting your senses is: don't. Just because you believe something to be true, just because you know it's true, that doesn't mean it is true.

Our internal life and external actions are steered by biological coctails to which we have neither immediate access nor direct acquaintance.

It is more parsimonious to assume that the sun goes around the Earth, that atoms at the smallest scale operate in accordance with the same rules that objects at larger scales follow, and that we perceive what is really out there. All of these positions were long defended by argument from parsimony, and they were all wrong.

It turns out your conscious mind - the part you think of as you - is really the smallest part of what’s happening in your brain, and usually the last one in line to find out any information.

When a male vole repeatedly mates with a female, a hormone called vasopressin is released in his brain. The vasopressin binds to receptors in a part of the brain called the nucleus accumbens, and the binding mediates a pleasurable feeling that becomes associated with that female. This locks in the monogamy, which is known as pair-bonding. If you block this hormone, the pair-bonding goes away.

Some men may be genetically inclined to have and hold a single partner, while some may not. In the near future, young women who stay current with the scientific literature may demand genetic tests of their boyfriends to assess how likely they are to make faithful husbands.

What has always surprised me when I walk into a bookstore is the number of books that you can find that are written with certainty. The authors tell some story as though it's true, but they don't have any evidence that it is true!