by Ibraheem Dooba
Most arguments are valid but not sound. Here’s the difference.
A valid argument follows the basic structure of rhetoric: a claim, supporting reasons and a conclusion.
“This candidate is the best person for the gubernatorial seat. This is because he’s well educated, he’s trustworthy and has achieved a lot of feats in his career. Therefore, voters should vote for him on election day.”
This is a valid argument. It satisfies the structure. It makes a claim, gives reasons and draws a conclusion from those reasons.
Let’s unpack that into three parts:
Claim: “This candidate is the best person for the seat.”
Reasons/premise: “He’s well educated, he’s trustworthy and has achieved remarkable feats in his career.”
Conclusion: “Therefore, voters should vote for him on election day.”
Why is this argument valid? It’s valid because it is logical. That means it draws its conclusion from the premise or evidence.
But arguments don’t only need to be valid but also fulfil a higher standard i.e. they need to be sound.
For that to happen, we only need to examine the middle part and ensure that it is true. That is, a sound argument is one in which the premise or reasons are true.
If not, the argument may be valid but not sound.
Therefore, for the example above, we are only interested in the middle which contains the three reasons the speaker used to draw their conclusion. So we can ask the question: is the candidate actually educated? Maybe he’s only credentialed. Also, how do we know for sure that he’s trustworthy? And lastly, where are the remarkable achievements and are they really remarkable?
(Taken from a court scene in the BBC TV show “You Don’t Know Me” on Netflix)
Claim: “This guy is the murderer.”
Premise: “The murder weapon was found on him, the hair of the victim was found in his car and there were traces of the deceased blood in his fingernails.“
Conclusion: “He has killed an innocent soul so the court should find him guilty and let him spend the rest of his life in prison.”
We already know that this argument is valid, but is it sound? That’s the question. So where should we poke to find the truth? Yes, the premise. That’s why lawyers attack the evidence or the witnesses.
In sum, to strengthen your argument, you should strengthen your premise. And to weaken your opponent’s argument, you should question the premise. And now that you know where to look, you can do it in one minute.
PS: This is also a good strategy to use in saving your wealth and honour from scammers and liars.