When discussing Artificial Intelligence I often hear people use the phrase "just a machine" to justify their belief that full AI is impossible or why computers could never be creative or have emotions. If no matter what we do, no matter how complex they become a machine will always be "just" a machine then this implies that there is something else that an agent could be? If humanity's last defense against accepting true AI is the word just then what do human's have that is beyond being a machine? My belief, and I think the belief of many AI researchers, is that there is nothing else that a thinking, acting, exploring, living mind can be other than a machine. That means that our computers will always be just machines, but so are we. The human mind is "just" a machine, that is, it is a wonderful, immensely powerful computational engine.
We aren't "just" machines. Rather, we are machines, full stop.
We should be proud of it or at least accept it. That way, when the machines that we've built can do everything we can we won't feel any more threatened or surprised than when our children grow up to be normal adults capable of everything we are.
For a great debate about the state of AI research and where it is (or isn't) going you must take a read of this post by Peter Norvig.