by Tim Sommers

Perseverance, the fifth NASA/JPL rover to land successfully on Mars, is currently looking for life there. What if it finds it?
The discovery of life on Mars would provide evidence that life is ubiquitous and likely to arise spontaneously under moderately favorable circumstances. It would be evidence that life everywhere is very similar – or, alternatively, very different – and give us more reason to suspect that there is life elsewhere in our own solar system. It could even suggest that we – you and I – are Martians. What evidence of life on Mars will not do, despite what some have argued, is make it more probable that human beings will go extinct. That last suggestion, proffered by Nick Bostrom and echoed by others, is (to use a technical, philosophical term) bonkers. So, I will leave it for last.
Perseverance is not just looking for life. It’s exploring the potential habitability of Mars for future missions, collecting samples that may be returned to Earth later, collecting instrument data, and taking spectacular photographs. I am excited about it as I have been excited about every mission since Viking 1 in 1976. (Excited, that is, once I recovered from my initial disappointment that there didn’t seem to be any dinosaurs on Mars. Don’t judge me. I was eleven years old.) But occasionally when I share my excitement with others, usually in the form of photographs, I get a dispiriting response. “It’s just a bunch of rocks,” more than one person has said to be. Either way, it’s still fascinating to me. But, well, maybe, it’s not just rocks. Maybe there is life on Mars.
For the purposes of this discussion, I am not going to distinguish between definitive evidence of past life and current, you know, actual life. Of course, it’s more exciting if there is actual respirating and metabolizing going on there right now. Fossils of extinct life are, well, still just rocks. But we are much more likely to find evidence of past life than anything living. To see why consider the question, why can’t we just see that there is or isn’t life on Mars? It looks pretty dead. Whereas a probe to Earth would detect life from orbit. Read more »

Over recent times, many books have been published with the aim of writing women into history and crediting them for the achievements they have made to the benefit of humanity more broadly. Janice P. Nimura’s The Doctors Blackwell is in that genre of women’s history and she effectively narrates the biographies of the first two remarkable women to study and practice medicine in the United States: Elizabeth Blackwell and her younger sister, Emily.
Cynthia, let me begin by asking you to describe your path to the book—a double path that led you to Joseph Brodsky and to George L. Kline.
Philosophy of science, in its early days, dedicated itself to justifying the ways of Science to Man. One might think this was a strange task to set for itself, for it is not as if in the early and middle 20th century there was widespread doubt about the validity of science. True, science had become deeply weird, with Einstein’s relativity and quantum mechanics. And true, there was irrationalism aplenty, culminating in two world wars and the invention of TV dinners. But societies around the world generally did not hold science in ill repute. If anything, technologically advanced cultures celebrated better imaginary futures through the steady march of scientific progress.



For some time, Sir Kazuo Ishiguro has been slyly replacing Dame Iris Murdoch as the author to whom I most regularly return. His enchanting and disturbing new novel, Klara and the Sun, his first since winning the 2017 Nobel Prize, is unlikely to diminish this trend. I wrote in a
have instrumental value. That is, the value of given technology lies in the various ways in which we can use it, no more, and no less. For example, the value of a hammer lies in our ability to make use of it to hit nails into things. Cars are valuable insofar as we can use them to get from A to B with the bare minimum of physical exertion. This way of viewing technology has immense intuitive appeal, but I think it is ultimately unconvincing. More specifically, I want to argue that technological artifacts are capable of embodying value. Some argue that this value is to be accounted for in terms of the 




