In Brave New World, "soma" is a drug which is used by the general population to provide pleasure and to neutralize any negative emotions. It has none of the deleterious side effects of actual drugs. Let's suppose such a drug exists. With what we know currently about neuro-chemistry, we can see that the pleasure that is achieved by productive acts is no different than pleasure produced by chemistry.
Let's ask the question of whether or not we would object to such artificial pleasure. Keep in mind that in the book "Brave New World" the use of soma doesn't have negative effects on productivity of the individual. The drug is freely available and does not distract the individual from his or her assigned tasks. Being rather Victorian in my outlook on morality, I would intuitively object to the use of soma except for pathological cases. However, I have difficulty in rationalizing my objections. From an evolutionary point of view, pleasure has been necessary in a goal-driven creature. However, natural evolution is a much less important force in our time. Society as a whole is now less dependent on large numbers of goal-seeking individuals and artificial pleasure would seem justifiable. If a gram of soma plus a Big Mac produce the same pleasure as a filet mignon, why not? If bicycling through a local neighborhood plus a gram of soma produce the same pleasure as bicycling along the Loire, why not?