A crystal uses outside energy to grow in an organized way
A virus does not consume energy itself
A plant does, but it does not think.
A sponge is an animal that does not think
A mouse is sentient
Humans are sapient

Where is the line for life? Do we decide because we are at a certain level? We ask as we are at the top of the pyramid. What if there are so many levels above us that some above us debate if we are alive?

What is life is relative to one’s perspective.\, In search for life we would therefor be simply search for those like ourselves because we can’t conceive all possibilities.