Distinguishing between fact and opinion is a vital critical thinking and reasoning skill. To make wise decisions and solve problems effectively, you need to know the difference between what people think (opinion) and what people know (fact); between what people believe to be true (opinion) and what has been proven to be true (fact). You should also be able to determine whether something presented as fact is really true or if you should accept it as a tentative truth.

Introduction

If you’ve ever watched the popular TV series CSI, you know that the investigators on the show rely heavily on evidence to prove their theories and solve their cases. What does this mean? It means that before they point any fingers, they use scientific proof to justify their claims. As a viewer, you may have an opinion as to who committed the crime in question—that is, you may believe one character over another. But according to the crime scene investigators, who did what and when is a matter of fact. That is, with enough evidence, they don’t believe—they know—because they can prove it.

Facts and Opinion

Before we go any further, let’s define fact and opinion. Facts are things known for certain to have happened, things known for certain to be true, things known for certain to exist. Opinions, on the other hand, are: things believed to have happened, things believed to be true, things believed to exist.

Believing and Knowing

Essentially, the difference between fact and opinion is the difference between believing and knowing. Opinions may be based on facts, but they are still what we think, not what we know. Opinions are debatable; facts usually are not. A good test for whether something is a fact or opinion is to ask yourself, “Can this statement be debated? Is this known for certain to be true?” If you can answer yes to the first question, you have an opinion; if you answer yes to the second, you have a fact. If you’re not sure, then it’s best to assume that it’s an opinion until you can verify that it is indeed a fact.

When you’re making decisions, it’s important to be able to distinguish between fact and opinion—between what you or others believe and what you or others know to be true. When you make decisions, assess others’ arguments, and support your own arguments, use facts, as they generally carry more weight than opinions. For example, if I try to convince my boss that I deserve a raise and I use facts to support my argument, I’m much more likely to get that raise than if I simply use the opinion, “I think I deserve one.”Notice the difference between the following two examples:

1.“I really think I should get a raise. It’s about time, and I deserve it. I’ve earned it.”
2.“I really think I deserve a raise. I’ve met all of my production goals since I’ve been here, my evaluations have been excellent, and I was employee of the month.”

Notice in the second example, facts supports the opinion that “I deserve a raise.” Furthermore, distinguishing between fact and opinion is important because people will often present their opinions as fact. When you’re trying to make big decisions or solve complex problems, you need to know that you’re working with evidence rather than emotions.

Truth and Lies

Label the following as either fact (F) or opinion (O).

1.“I believe that the government has evidence of contact with aliens hidden in Roswell, New Mexico.”
2.“The government has evidence of contact with aliens hidden in Roswell, New Mexico.”

You didn’t by chance mark the first claim as O and the second claim as F, did you? If you did, it’s easy to see why. The first claim is presented as an opinion (“I believe”), and it is therefore clearly an opinion. The second claim, however, is presented as a fact. But is it true? Is it something known for sure? Well, it can’t really be proven or disproved, unless you have access to secret government documents. Statement 1 is what is called a tentative truth, since it is neither a fact nor an opinion. Until the truth of that matter can be verified— especially a matter that has been so controversial for so many years—it’s best to hold on to a healthy measure of doubt. Tentative truths need not deal with conspiracy theories or other issues of major importance. They can deal with issues as simple as this: Volvos get 30 miles per gallon.

This is a matter of fact, and it sounds like something that should be accepted as true, but unless you got in a Volvo and drove around, you may not be able to verify it. You can tentatively accept it as fact especially if the source is credible. Credibility is the key determinant of whether you should accept facts you can’t verify yourself.