- Life is technically impossible to define, because there may be undiscovered alien life completely different from that on Earth, and one definition will not be able to include every kind of living organism. (In science, there are always exceptions)
- It would then be impossible to detect completely different kinds of alien life, because we wouldn’t know how to design the right experiment. So we will only be able to detect life that’s chemically similar to life on Earth.
What’s Interesting: The opposing stand towards defining life. Do we really need to define it?
Definition of life: see reflection a5