This discussion is not based on morality. It is based exclusively upon observation of the human mind. Our mental states are solely chemical based. We are just machines after all. Nature has provided us with various means of reaching states which may be called pleasurable. Animals seek pleasure and wish to avoid pain. The things which in nature give us pleasure are those things which are generally good for us. We take pleasure in sex, food, rest, drink and even things less tangible such as success at the things we do.
Humans, being the clever little apes that we are soon learned ways to short-circuit the pleasure systems in our brain through the use of chemicals which mimic natural pleasures such as alcohol, opium, and cocaine. The problem with sense pleasures of these kinds is that we are designed to become accustomed to these sensations and to build tolerances to them requiring more. The reason is purely electrochemical.
The upshot of this is that if we attempt to chase pleasure without balance and moderation the system breaks down and we fall into addiction and our health suffers and the pleasure becomes harder and harder to attain. Moreover, on a psychological level, we cease to find contentment and we find ourselves increasingly depressed and anxious which leads to further attempts to cure this with sense pleasures which lead to a further degradation of the system.
There is a different source of pleasure which we may call joy. Joy cannot be attained through artificial means. Joy comes from leading a life of the spirit. This joy does not tear our body down rather it increases our overall health and contentment. We do not build a tolerance to joy. The more we have the greater our sense of contentment and well-being.
Nurse The Soul 