I’m not persistently sober because of “adverse effects” (I assume you are referring to physical illness) and if any of you are you won’t last for long – unless of course you have some medical disorder which makes the consumption of drugs lethal. Simply put, as the OP pointed out, some drugs are not adverse to one’s health if consumed in a certain fashion – and if health is your reason for rejecting intoxication or altered states of consciousness, you might as well educate yourself and begin eating pot brownies.

Straight edge by itself is fairly worthless – it is more useful as a label than anything else, and without an underlying framework of ethics it falls apart. It is for this reason that I have always tried to avoid discussing straight edge and instead offered perspectives on how to live well – the former implies adherence to a label without the ‘why’, the latter implies a life quest for sustainable, examined living. I think many people who call themselves straight edge have not examined their reasons, and without such an examination, will grow out of it.

For me, sobriety, temperance and vigilance are necessary faculties for being the type of person I want to be. Altered states would fray the rationality I hold so dear and make it more difficult to search for the truth of matters. Sobriety is also necessary for properly adhering to one’s duties, whether it be loyal friendship or duty to ideals, the state or principles. Furthermore, desire and yearning for things which we cannot control (such as the objects of our desire) is the principle cause of agony in the world and I would rather desire less and as a consequence be happy more. Lastly, one cannot fend off the wolves if  drunk:

“And what do I do?” said the surly voice of the small man. He was short and stout, was not very smart, not very good looking, not very good at anything, so he did odd jobs around the grocer and the town square.

Arminass poured two beers. He handed one to the surly small man. “You work odd jobs, and do what others tell you to do, and do not worry about the problems of this town, ” said Arminass.

“That’s what I always did, ” said the small man. “You’re just like the rest of them, keeping me down. If it weren’t for you, I would be rich.”

Arminass pointed across the square. “That grocer was an orphan who had no money, but now he has a store. Did you have two parents?”

“Yes, ” said the small man.

Arminass waved to the town policeman. “That man started out life as a small baby, fighting for life, blue in the face. Were you born normally?”

“Well, yes I was, ” said the man.

Arminass thought, told the man to drink his beer, and then pointed to a woman who was tending small children. “Her husband died and left her with no money, but now she has her own store of metalworks and a healthy family. Is your wife alive?”

“Why, yes she is, ” said the man.

Arminass turned to him and said, “You can see there is a reason why you are what you are, and it is not that I kept you down, or anyone else did. You are at the position life has selected for you. What you should do is rejoice in your freedom from having to worry about the complications of life, and spend your time enjoying it. In fact, I suggest you drink and be merry.”

The man drank. “Why are you not drinking?” he asked.

“I must consider the safety of the town, ” said Arminass. “If tigers show up and I am drunk, I cannot stop them. If a fire breaks out and I am drunk, I cannot smother it. If bandits appear and I am drunk, I cannot fight. This is why you should be glad not to have to serve as I do.”

The man considered Arminass. “But isn’t that boring?”

“No. It is what life made me to do, and I find that while I would like to be drunk sometimes, I feel better if I am doing what I am made to do, so that my life may have meaning.”