Abstract:
Sufficient conditions would include confirmation of extraterrestrial intelligence.
Accordingly the SETI-projects of NASA and some universities
are explained and examined. The possibility of UFO's is taken into account
and evidence evaluated. In respect of philosophical considerations,
the validity of inductive strategies is investigated as well as
epistemological problems relating of rational communication. Theological
considerations bring to the fore the imago Dei problem. It is concluded
that in the light of both neccessary and sufficient conditions the issue
no longer is of a scientific fiction nature but is on a firm scientific path.