a difference of opinion

A: I just can't understand how you can keep stuffing your body with such chemicals. You know they are harmful right? You prefer the momentary buzz over long term happiness, it's irrational.
S: I can't understand how you can stuff your body with harmful chemicals either, Ameen.
A: What? You know I have never touched alcohol or drugs.
S: You haven't? What about the caffeine you guzzle down each morning, or the two aspirin you take everyday before going to sleep, or the nicotine those cigarettes carry? Aren't those drugs too? they alter your state of conciousness and have widespread - and harmful - effects on the body. So look at yourself before you preach sobriety.
A: What I consume are 'drugs' in the scientific sense, not the recreational kind you do. Yes, they both change how the body works, but your kind is worse by comparison, its effects are more drastic and it invariably leads to addiction. Barring the cigarettes, I have no excuse for that, it's been a bad habit for too long
S: So you concede, both of us take drugs, in fact the whole world does. Now to you second point, are you seriously saying coffee or prescription drugs are not addictive? Have you ever seen a person hooked on anti-depressants? What leads to addiction is indulgence, moderation keeps everything ticking. This is universal; ask the morbidly obese who had too much 'wholesome food' or the diabetic who had too much chocolate.
A: You are not defending your actions, you are just pointing out how everyone in the world is equally flawed. You don't have an objective justification and you know that.
S: Life is hard, that's all the justification I need Ameen.