An opinion backed by facts and principles quietly becomes something stronger: an argument
Two people can accept exactly the same facts and still reach opposite conclusions. That gap is where opinion lives. Yet opinions are not all equal: one can be better supported than another, and in courts, laboratories and Brussels, a formal opinion can carry real weight and even legal consequences.
The basic distinction is verifiability. A fact is something experts can agree on by checking; an opinion is a judgement or viewpoint that stays inconclusive. Some opinions concern matters with no final answer at all. Others dispute established facts by leaning on the fallacy that everyone is entitled to their own view. When an opinion is propped up with evidence and principles, it turns into an argument, and arguments can be compared: analysing the support behind each shows which is stronger. People rarely shift position unless someone offers them a new argument.
Opinions also add up. Public opinion is the combined attitude of a city, state or country, and consumer opinion is the same idea applied to users of a product. Asking everyone is usually impossible or too costly, so both are estimated from representative survey samples. Political scientists and psychologists study group opinion in juries, committees and legislatures, asking how conformity and polarisation shape collective choices.
Scientific opinion sits higher on the ladder because it appears in peer-reviewed journals and carefully edited textbooks, or comes from professional and governmental bodies. It is not the same as scientific consensus, the prevailing view across a whole field. Individual scientific opinions can be partial, provisional and conflicting, and some openly clash with the consensus.
Law turns opinion into a formal instrument. An attorney's legal opinion letter, usually written for a business deal, gives a professional judgement but guarantees no court outcome; if it is careless, the lawyer can be sued for malpractice. A judicial opinion explains a ruling by laying out the established facts, the binding principles and how one was applied to the other. In the European Union, the Commission's reasoned opinion under Article 258 formally demands that a member state comply with EU law, typically within two months, while national parliaments get eight weeks to object to draft laws on subsidiarity grounds.
Source: Opinion
