An interest in the subject at hand and willingness to learn from it. Well forget the last part, many people have opinions and they are NOT inclined to learn. So - just an interest in the subject would be required.
Not sure about 2 people having the same recipe..
No you can't avoid disagreement.
Just when I was getting used to yesterday, along came today.
What are the essential ingredients needed to form an opinion?
And can any two people have the exact same opinion recipe?
Is disagreement something you can avoid? Are you supposed to?
1. Life experience. Now, for a 'good' opinion then you need: apart from life expereience: wisdom, sagacity, good intuition, sensibility.
2.hardly as 2 people have diferente life experiences.
3.you can avoid dissagreement somehow, as far as you PUT YOURSELF IN THE OTHER PERSON'S SHOES. i MEAN WHEN YOU TRY TO FEEL WHAT THE OTHER FEEL.
We are suppose to at least try to understand as much as we can the other.
Life is exchanging: 'things' , expereineces, opinions, Money, goods...love