How not to be fooled by 7 common, but flawed, tools of persuasion

The ability to exchange differences of opinion in a reasoned and respectful manner is vital – both to personal relationships and to the health of society. Yet these sorts of healthy dialogues sometimes seem in short supply.

There are often types of arguments put forward that sound convincing, and are certainly passionate, but actually lack credibility or internal consistency.

Being deliberate in what we think and believe means having the intellectual discipline to spot logical fallacies, and also refuse to use them ourselves.

Here are 7 flawed types of arguments to watch out for, in your own thinking or that of others.

1. Ad hominen

A favourite of many, sure to lower the level of any argument immediately – just attack the speaker instead of the argument. Infer that whatever flaw you point out – real or imagined – undermines the truthfulness or logic of their argument.

For example –

Senator Smith’s point about health care reform can’t possibly be valid since he hasn’t released his tax records and therefore must be hiding something.


2. Strawman

Another very popular and flawed way to debate is to create a strawman argument. Basically, you present a caricature or over-extrapolation of the other person’s true argument, then explain why that position (rather than their actual one) is flawed.

For example –

The Obamacare plan basically wants to provide free health care for all treatments of all ailments to all people forever. That won’t work because…


3. Post hoc ergo procter hoc

Latin for ‘after this, therefore because of this’, it means to imply or specifically state that because B follows A, B must have been caused by, or be somehow associated with, A.

For example –

All I know is that I never had any trouble with my daughter talking back to me when the last Prime Minister was in power. The fact that she was 9 months old when the current Prime Minister won is beside the point.


4. Begging the Question

Now, though this phrase is commonly misused to mean ‘raising the question’, it actually means to imply an unproven conclusion in one’s premise. That is, you need to use an assumption for which you have no evidence, as evidence for your arguments conclusion.

For example –

When discussing someone who has four attractive and successful children, but of whose family life you have no actual evidence –

Mr Thompson would be great for this position as Minister for Families because he’s such a great father.


5. Cherry Picking

Easy – just use all the evidence you can that backs up your point of view, and don’t even mention any of the evidence that contradicts it.

For example –

I’ve eaten as much sugar as I want for 20 years and I’m still skinny and healthy. It’s the same with all my brothers and sisters. Therefore sugar can’t be a cause of disease or obesity.


6. False Analogy

Everyone loves an analogy. Find a good false one, and people will buy into the argument without even realising it doesn’t make sense. Just establish a similarity between two things, and then extend that similarity beyond its supportable bounds.

For example –

Children are like plants. You can’t force their growth. All you can do is provide the right environment, the right nutrients, the right care and attention, and then trust that they will respond to that, and grow into all they are meant to be. And both children and plants need their own space. You can’t plant two trees right next to each other and then expect them both to be able to grow to their full size. One will stunt the other. In the same way, it is obvious that making two children share a room will inevitably lead to a situation where it is impossible for both children to develop healthily.


7. Appeal to motive

A classic move by many. Similar to ad hominem, you can use the appeal to motive tactic by highlighting a relevant attitude, connection or belief of the person or organisation in question to undermine the credibility of their conclusion. This will appear terribly convincing, without actually requiring the demonstration of actual flaws in their conclusion, when in fact both the accused connection and the disputed conclusion can be simultaneously true.

For example –

The pharmaceutical company paid for this study about whether or not morphine is effective in relieving pain. Of course the study proves that it is – they are going to make money selling morphine. Therefore the study must be flawed and morphine probably doesn’t relieve pain.


So there you have it – 7 common ways that we lower the level of our disagreements and confuse the matter at hand.

Let’s be on the lookout for these so that we can all be a part of deliberately raising the level of our thinking, personal discussion, and even our public discourse!