Is it permissible to become addicted to something?
Regarding smoking marijuana, R. Moshe Feinstein (Iggeros Moshe, Yoreh De'ah 3:35) wrote:
It causes a great desire--greater than the desire for food and similar items that are necessary for one to live--and some people will not be able to resist this temptation. This falls under the serious prohibition mentioned regarding the "rebellious son," about his great desire for food, even if for kosher food. Even moreso one cannot bring oneself to an even greater desire, especially for something for which there is no human need and is prohibited itself.It seems that R. Feinstein is of the view that one may not intentionally make oneself addicted to a substance.
However, in his responsa regarding smoking cigarettes (Iggeros Moshe, Orah Hayim 2:49, Hoshen Mishpat 2:76), R. Feinstein does not once mention addiction when, to my knowledge, cigarettes are more addictive than marijuana. What's the difference? Is it only that marijuana is otherwise prohibited and one may not become addicted to something already forbidden? But if something is permitted then one may become addicted to it?