Both of you are right and wrong. Cigarettes contain many more chemicals which are designed to make the user addicted. These chemicals result in lung and mouth diseases. There are also sever carcinogens in them. However, marijuana has none of the additional chemicals that come with cigarettes. This doesn't mean weed is not bad for you though as it does contain carcinogens of its own. Expect that's the same as saying the air we breath is not dangerous to use. Any foreign chemicals in the air will damage our lungs. This is because pollution and such, but that's not my thing. But seriously. Anytime you breathe something other than air you are damaging your lungs. Enough of that though. In the end neither one is good for you, but I would suggest weed to someone over cigarettes any day as long as it won't affect their job or way of life. Please educate yourself thoroughly on a topic before debating it with someone. It'll do both parties some good. Even if you disagree you'll be sourcing knowledge that others can use and you may even take something away for yourself. [spoiler]I am not siding with either of you and I'm not trying to count your short comings either. I'm simply trying to state the facts.[/spoiler]