Self intoxication is a phenomenon that is spread throughout the animal kingdom and there are countless examples of it. It occurred to me the if the man was a hungry predator the squirrel would be dead as its abilities of self preservation had been diminished. So why then has evolution not breed out the desire to engage in self intoxication?
I postulate that there must be some advantage in engaging in self intoxication that out weighs the dangers caused by the diminished abilities of self preservation. Some possible mechanisms are;
1) Life is hard, not just for humans. It's possible that these episodes of abandon help to maintain motivation.
2) Barriers to reproduction my be broken down by intoxication. This would seem especially true in the human species.
3) Altered perception may help you see things differently and enable you to see solutions to problems. A large number of creative people claim to get inspiration from intoxicants.
So if self intoxication is both natural and beneficial (from an evolutionary perspective) then why do humans see it as a big problem?
I have a theory about this, if anyone is interested?
Once man started farming, a debate that is not settled is whether it was first for beer or food. Fermented wine or beer would keep indefinitely, water would not. Much safer to drink wine or beer than water, many places and times in history.