For instance, for a recovering alcoholic to walk into a bar is stupid and can tempt him to drink…this is an occasion of sin. However the act of walking into that bar is not a sin in and of itself.
Actually, I think this is incorrect. If the act of walking into the bar is voluntary (e.g. no physical force was used) and not necessary (e.g. to get a fellow alcoholic to leave would be necessary in charity), then it is a sin. If not, it would basically be impossible for an alcoholic to commit any mortal sin related to drink.
Alcoholic walks into a bar, for no reason other than he wants to go into the bar. [Not a sin according to your definition.]
Alcoholic orders and drinks a drink. [Not a mortal sin, because the habit and addiction take away the possibility for full consent of the will once the alcoholic is in the setting where everyone is drinking.]
Alcoholic orders and drinks several more drinks. [Not a mortal sin, for the same reason as above, and progressively because full consent of the will is not possible in a drunken state.]
Alcoholic leaves the bar and robs a liquor store, commits adultery, kills someone while DUI, etc. [Not a mortal sin because of being drunk and not in control.]
And so forth. Voluntarily placing yourself, without any necessary cause, in a position where you know you are unlikely to be able to resist temptation is a sin. I don’t think that the Church has a specific teaching on whether that sin is of the same gravity as the sin you are tempting yourself to, and my personal opinion is that it is somewhat less. But it is still a sin. If it is a sin to tempt others to sin (and it is) then it is also a sin to tempt yourself to sin.
If you know that you can’t avoid drinking 8 drinks if you have one, and you know that you cannot avoid having one drink in a bar, then choosing to go into a bar basically is the same sin as choosing to have 8 drinks. The degree to which you might be able to withstand temptation when in the bar or after the first drink, determines how much less serious the sin of going into the bar is compared to the sin of having 8 drinks. (This part is not official Church teaching AFAIK, but it is compatible with it.)
Two other things related to this issue:
Every time we pray the Our Father, we ask that God lead us not into temptation. It is a little hypocritical to pray this if we are going to turn around and lead our own selves into temptation.
In the Act of Contrition that I have used from my childhood, which I think is a pretty common one, we pray something like: “
I firmly resolve, with the help of Your grace, to sin no more and
to avoid the near occasions of sin.” (some forms say “to avoid whatever leads me to sin” instead.) If we have resolved to avoid them, in the presence of a priest acting in persona Christi, and then we do not attempt to avoid them, that is sinful.
Just my :twocents:
–Jen