Because men, compared to male chimps, have such relatively small testicles (large testicles indicate a species where many males mate, one after the other, with the same female), we might guess that promiscuous societies were uncommon in the immediate human past.

The suppression of uncomfortable ideas may be common in religion or in politics, but it is not the path to knowledge, and there's no place for it in the endeavor of science. We do not know beforehand where fundamental insights will arise from about our mysterious and lovely solar system. The history of our study of our solar system shows us clearly that accepted and conventional ideas are often wrong, and that fundamental insights can arise from the most unexpected sources.

It does no harm to the romance of the sunset to know a little bit about it.

Time spent with children is time well spent. Their little minds are not constrained by 'reality' or focused upon goals. Anything and everything is possible. Imagination will often carry us to worlds that never were. But without it we go nowhere.

Before we invented civilization our ancestors lived mainly in the open out under the sky. Before we devised artificial lights and atmospheric pollution and modern forms of nocturnal entertainment we watched the stars. There were practical calendar reasons of course but there was more to it than that. Even today the most jaded city dweller can be unexpectedly moved upon encountering a clear night sky studded with thousands of twinkling stars. When it happens to me after all these years it still takes my breath away.

Since World War II, Japan has spawned enormous numbers of new religions featuring the supernatural.... In Thailand, diseases are treated with pills manufactured from pulverized sacred Scripture. Witches are today being burned in South Africa.... The worldwide TM [Transcendental Meditation] organization has an estimated valuation of $3 billion. For a fee, they promise to make you invisible, to enable you to fly.

My long-time view about Christianity is that it represents an amalgam of two seemingly immiscible parts-the religion of Jesus and the religion of Paul. Thomas Jefferson attempted to excise the Pauline parts of the New Testament. There wasn't much left when he was done, but it was an inspiring document.