Alisha’s unwillingness to eat animal products is a rule of personal conscience, enforced by self-discipline.
Dietary choices can be the result of different rules, but in this case Alisha refuses to eat animal products because of her concern for animal welfare. This is a therefore a matter of her personal conscience and her wish to do what she thinks is right. Other people may behave in similar ways for different reasons, such as religious beliefs but, from the given facts, that is not so in this case.