The Thomas Merton article provided by error 503 touched a nerve.
Taking drugs is one of the most self-centered actions possible. A person can find detachment from the use of drugs only during the high, and during this time his ability to reason—the ability that separates him from the animal, that makes him in God’s image—is faded.
I thought what was bad about drugs is that they do harm to the human body, both in their addictive properties (enslaving us) and their physical damage. Is the high itself bad? I guess it depends on the extent the drug obscures reason. If it totally and completely occludes it, I could see that (because you can no longer be responsible for your actions). But if it is a partial eclipse, then...? As an aside, I'm not defending drug use. I simply think that if the thing about drugs that is wrong is that it impedes reason, well, other things than drugs do that.
For don't we partially eclipse reason all the time? Joggers/runners do it on long runs. (The old joke with much truth goes: after a fight with your wife, go out for a good run. After 2 miles, you'll forget why it was so imporant to you, after 5 miles you'll forget what you were arguing about, after 10 miles you'll forget you have a wife). Every night, for 7-8 hours, we shed rational-thinking for sleeping & dreams.
Eve's vast post acknowledges this in the context of rock music and the validity of the "ecstatic experience". Sexual activity is sans reason. The use of alcohol is nearly universal. What separates us from animals is reason, but nearly all of us intentionally flee from it (at least partially) at regular intervals.
Dappled Things quotes Thomas Merton (speak of the devil) saying this:
The salvation of man does not mean that he must divest himself of all that is human: that he must discard his reason, his love of beauty, his desire for friendship... A Christianity that despises these fundamental needs of man is not truly worthy of the name.
But is it not inhumane to divest oneself of all that produces detachment in other ways than via love: i.e. through travel, rock music, physical exercise, etc.? We are animals too. On Star Trek the most inhuman person is Spock, whose reason was always unclouded.
Aquinas, who believed bodily pleasures much inferior to intellectual ones, said:
"Bodily pleasures hinder the use of the mind by distracting it, occasionally conflicting with it, and sometimes (as in the pleasure of drinking intoxicants) by fettering it."