It is from the progeny of this parent cell that we all take our looks; we still share genes around, and the resemblance of the enzymes of grasses to those of whales is in fact a family resemblance.

The gift of language is the single human trait that marks us all genetically, setting us apart from the rest of life.

Maybe there is a single spot, just one, where living organisms are holed up. Maybe so, but if so this would be the strangest thing of all, absolutely incomprehensible. For we are not familiar with this kind of living. We do not have solitary, isolated creatures. It is beyond our imagination to conceive of a single form of life that exists alone and independent, unattached to other forms.

We leave traces of ourselves wherever we go, on whatever we touch.

Given the opportunity, under the right conditions, two cells from wildly different sources, a yeast cell, say, and a chicken erythrocyte, will touch, fuse, and the two nuclei will then fuse as well, and the new hybrid cell will now divide into monstrous progeny. Naked cells, lacking self-respect, do not seem to have any sense of self.

Mistakes are at the very base of human thought, embedded there, feeding the structure like root nodules. If we were not provided with the knack for being wrong, we could never get anything useful done. We think our way along by choosing between right and wrong alternatives, and the wrong choices have to be made as often as the right ones. We get along in life this way.

Perhaps the safest thing to do at the outset, if technology permits, is to send music. This language may be the best we have for explaining what we are like to others in space, with least ambiguity. I would vote for Bach, all of Bach, streamed out into space, over and over again. We would be bragging of course, but it is surely excusable to put the best possible face on at the beginning of such an acquaintance. We can tell the harder truths later.