The definition of Rational is : Based on or in accordance with reason or logic:
As the reasoning part of your brain is also the part of your brain involved in the Alcoholic Voice. (i.e., you are reasoning with yourself), your rational brain is giving you excuses, reasons and logical ways to avoid being sober and to drink.
If I see a bottle of wine (like yesterday) and pour it down the sink. My rational thoughts are telling me, its a waste, it costs money. Another part of my brain is reasoning with this rational brain and saying, (yes but it is harmful).
This conflict is not rational. It is not rational to have two parts of the brain in disagreement with each other, therefore irrational thought in the face of reason must win out.
(Do not confuse rational with being right or wrong)
If I irrationally thoughts that sobriety is the way forward or counterbalanced by the rational thoughts that its ok to drink. Then irrationally is the right and rationally is wrong.
Is it rational to put your hand in a hot fire. No. So why would I do it ?
I wouldnt.
But is it rational for me to drink alcohol harming my body. No. So why would I do it ?
I would. (there is an error with this line of thinking).
So the exact opposites must apply.
Is it rational for me to be drinking alcohol harming my body. Yes. So why would I do it ?
I wouldn't. (Because I know it is harming me).
This is the dichotomy of addiction. Rational thoughts are used against the person and so perpetuating the addiction even though they know its wrong. This is why the relapse rates are so high, if drinking was irrational, we simply wouldn't do it and none of us would be here.
It is the fact that an alcoholic sees drinking as rational, whereas other see it as irrational is the root of alcoholism and what separates us from so called "normal drinker".