This follows from property identity: if X = Y, you can’t have X without Y, or Y without X. For example, you can never ask for six bottles under the condition that you will not be given half a dozen bottles. This is because six is just the same as half a dozen. This is true of the identity of mental and physical states. For example, if the physical realization of pain is C-fiber firing, then it cannot be anything else but C-fiber firing. This is property identity theory. But the multiple realizibility of mental states opposes this claim. If pain is related to both C-fiber firing and D-fiber firing, you can have pain without C-fiber firing (given that you have D-fiber firing), and you can have pain without D-fiber firing (given that you have C-fiber firing). What this also implies is pain is not identical to either one – you cannot have six bottles without having half a dozen. Therefore, I ask myself the following question, is there valid reason to think that mental states are in fact multiply realizable? I believe so.
Alien beings are often conceived as having similar mental attributes to humans, albeit physically different. Intelligent beings develop the capacity to select advantageous mental states to sustain life force. For example, if I am unable to feel pain (which is a mental state), it won’t be possible for me to recognise any physical experience which is life threatening. Resultantly, I would cease to exist, thus failing to reproduce and pass on my legacy. Likewise, my cognitive capacities such as intuition and decision making abilities enhance my awareness about surroundings and help me do the right things at the right time. Without these traits, I wouldn’t have been able to sense danger and would expose myself to potentially harmful situations, which, again, would make me susceptible to extinction. Therefore, one can rationalise that an intelligent alien creature living somewhere in the universe would have