I don’t think anyone would be able to provide a definitive answer for this, but the most you’d be able to get here is opinions. If I can throw mine in, my opinion is that, yes, it is sinful, because of our doctrines on life.
We believe that it is always wrong to cut short any human life, and natural death is what’s preferred. We could voluntarily die when someone is telling us to deny Jesus (as many saints did, like Miguel Pro) or if there’s an altruistic end (like Maximilian Kolbe, who died in place of another man). But hastening our deaths is wrong. God gives humanity life, and only God can take it away, and to violate that without good reason is sin.
Then again, if that’s the principle we’re taking, then it means that it’s a sin not to be a vegetarian (even though Jesus himself wasn’t a vegetarian – we see in the Gospel of Luke that he ate fish), and it’s a sin not to wear a safety belt, and it’s a sin to work too hard (even though the hard monastic work ethic is something we should be proud of), and it’s a sin to do anything else that would lead us to unnecessarily-early graves.
On the other hand, I believe that we should do our best to work for God. If we die early because of the hard work, then that’s great. But again, would it be a sin to work to that breaking point? Or does it qualify as working for a truly good purpose? Does it only matter when it’s *direct * hastening of death, or are
indirect factors and choices also sinful? I think it’s safe to say that the indirect route is less sinful than the direct route, but that indirect route a sin at all?
It’s interesting to note that Pius XII also was a smoker. But the thing is, he died in 1958, and I don’t know whether or not they recognised smoking to be hazardous by that time. If the world knew how bad it is by that time,
The liberal answer you’d get would probably be, “It depends on your conscience.” Conservatives like me would probably try to give you a more absolute answer. In my opinion, it is wrong.
But again, that’s really all just opinion. You bring up a really interesting philosophical point.
Sorry! I know this isn’t an answer to your question, but maybe it’ll give you more thoughts to chew on. It certainly got the wheels in my head spinning.
If I can make a suggestion, Lent is coming up. Do yourself a favour and stop smoking, and use your cigarette money to feed some homeless people on the street. After Easter, think about it a bit and evaluate how you feel.
Hi, a guy called SID here. I’m trying desperately to give up smoking much as I’m trying to give up mortal sin (sins of the flesh etc.). The thought has hit me, is smoking itself a mortal sin? Am I slave to my passions because I “sly” (slip) a cigarette? The body is a temple of the Holy Spirit, etc. – and let’s face it, inhaling smoke into your system is as unnatural as it gets. After all, God didn’t invent cigarettes, I actually believe they’re a product of the dark side, but let’s not get into that, OK?

But God didn’t intend Adam and Eve to smoke. I know there are a lot of things around today that weren’t around to our ancestors (the Hebrews or the medieval Christians) but is smoking tobacco sinful?
Many thanks for your (name removed by moderator)ut,
SID.