That depends on the logic and the topic.
If my child is old enough to go to college then they are legally an adult and I need to respect that. I can disagree or encourage them to do something else, but I cannot make choices for them and if I bully or threaten them into doing what I want, I would be putting my relationship with them on the line.
However, when they are under my care, as in, I am legally responsible for their actions. They may disagree, but they need to be able to tell me why their option is better in a manner befitting their intelligence. IE. discuss, not throw a temper tantrum because I don't like it.
They must respect that I don't like it, but will help any way I can, as long as there is no foreseeable future, and always must respect the "you made your bed" principle. They have the freedom to choose as long as they will not be harmed or harm others, but if it doesn't turn out the way they like it, I'm not to blame, and they should turn to the back up plan (which would be part of the discussion when we disagree).