Thank you for your encouraging letter of the 14th. I hope you will forgive the too impassioned tone of my memorandum; the
understanding with which these views have been received speaks against the need for it. I was fearful that a demonstration
lunar probe might be set off before there was time to assess whether my concern was valid or not. The purport of your letter
is very hopeful against this.
There will now be the problem of a studious assessment, which I have hoped might be sponsored by the NAS. I understand that
a symposium will be held before long on the uses of satellites in biological research, and this might furnish the necessary
forms. There are many plausible arguments against Arrhenius' theory and I do not want to be put in the position of defending
it. I simply felt the issue was too important to be disposed of by casual a priori argument.
Curiously enough, professional biologists have taken little part in speculations about extra-terrestrial life. This may have
something to do with the currency of such proposals as that oxygen is a sine qua non for any intelligent life. We do badly
need a channel of communication that can focus the knowledge and experience of specialists in several fields on these problems.