  There is a close interrelation between Searching for Extraterrestrial
Intelligence (SETI) and Messaging to Extraterrestrial Intelligence (METI). For
example, the answers to the questions "Where to search" and "Where to send" are
equivalent, in that both require an identical selection from the same target
star lists. Similar considerations lead to a strategy of time synchronization
between sending and searching. Both SETI and METI use large reflectors. The
concept of "magic frequencies" may be applicable to both SETI and METI. Efforts
to understand an alien civilization's Interstellar Messages (IMs), and efforts
to compose our own IMs so they will be easily understood by unfamiliar
Extraterrestrials, are mutually complementary. Furthermore, the METI-question:
"How can we benefit from sending IMs, if a response may come only thousands of
years later?" begs an equivalent SETI-question: "How can we benefit from
searching, if it is impossible now to perceive the motivations and feelings of
those who may have sent messages in the distant past?" A joint consideration of
the theoretical and the practical aspects of both sending and searching for
IMs, in the framework of a unified, disciplined scientific approach, can be
quite fruitful. We seek to resolve the cultural disconnect between those who
advocate sending interstellar messages, and others who anathematize those who
would transmit.
