Whenever a conversation flairs up with my friends about space, planets other than our own and the possibility intelligent life elsewhere in the galaxy, I am always afraid that someone will over hear our conversation and think we are inner city equivalents of a stressed dairy farmer from Iowa who claims to have been abducted and experimented on by aliens. Just to be safe I tend to keep my voice down during such conversations.
However over recent years since the observation of the first planet orbiting a star other than our own (extrasolar planets, as they are known) in 2002 planet hunting, and hunting for planets which may harbour life, has become scientific mainstream, with talk of intelligent life regularly featuring in popular science magazines, especially when a planet which seems to resemble Earth is found, such as Kepler-10b which is the planet closest to the size of Earth, and a potentially good contender for intelligent life, that has so far been found. As it turns out Kepler-10b is too hot to harbour life, with one side of the planet permanently facing its star as hot as1400 °C, which is hotter than lava flows here on earth.
However with discoveries like this coming in, and more than 518 extrasolar planets charted to date, we may soon come across a planet that is the right size and distance from its star to harbour life. Philosophical questions arise from such a notion. Serious questions will arise for the three great monotheistic religions such as how are their doctrines that tell us that we are the centre of everything that exists continue to be tenable if we were to find life elsewhere? Would we have any chance of communicating with them or understanding them in anyway? After all it was Wittgenstein who alluded to the life of a lion, explaining that even if it could speak English, we would have no chance of understanding it because our lives and perspectives would be so different. And perhaps the question most alien invasion films have troubled themselves with; would we even want to discover them, or them to discover us? In many films featuring humans encountering aliens the encounter has been less than friendly (OK, Ill grant you ET). Worryingly Stephen Hawking has spoken about this, stating that mathematically it seems very likely their could be intelligent life in our galaxy, but that we should be doing everything we can to avoid their attention as they may be violent, citing the violent tendencies of the only intelligent life form known to us; ourselves.
Whatever the answers to these questions may be, if we do discover a planet which can harbour life and perhaps on day discover life on another world, being human just won’t be the same.
Related articles:
Cosmological Arguments from Contingency
The Later Wittgenstein and the Philosophy of Religion
The Philosopher's Eye 
We cannot even understand whales. Many studies suggest that they are very intelligent though. Oh, but wait, they are intelligent, but not the way we like. They are not as interesting as an imaginary alien who could have all the anthropomorphic qualities we want. Maybe whales have a religion too, we know that they can communicate and transmit a culture from one generation to another. If humans were more interested in intelligent forms of life on their own planet, maybe I could believe they would notice other forms of life in the universe…
Well, since we’re the only intelligent life form we know, that makes humans easy targets for comments such as the one above.