Are We Presuming or Assuming?

By Dave Elniski, MA, CTSP, CRSP, ATCL, Industry Advisor, Safety and Compliance, Alberta Motor Transport Association

What’s the difference between a “presumption” and an “assumption”? The definitions are quite similar, but there is a difference. According to the Merriam-Webster Dictionary, an assumption is something we accept as being true without evidence. A presumption, on the other hand, is something we accept as being true without proof.

Understandably, many use these words interchangeably. However, there’s a significant difference between something unproven yet accepted (i.e., a presumption) and something accepted without evidence (i.e., an assumption). Proof is certainty. Philosophically speaking, proof is practically unattainable outside of math and physics. Evidence, though, is different. We can have lots and lots and lots of evidence that something is true without it being proven as true.

When we presume, we expect something to go/act/be a specific way even though we’re not 100% certain. When we assume, we do the same but without any evidence to give us reason to believe so. The implication is that we have more confidence in a presumption than in an assumption. A presumption only stops short of proof, meaning we can have a lot of evidence to support it. An assumption? Not so much. We can assume something to be true with no evidence at all.

Perhaps that’s why there’s a saying for assumptions often attributed to Oscar Wilde: ASSUME makes an ASS out of U and ME. Interestingly, even attributing this quote to Wilde is an assumption according to the following article, which I recommend reading if you’re interested in this sort of thing: www.laboremploymentreport. com/2024/01/25employers-when-youassume-you-make-an-ass-out-of-u-andme-oscar-wilde-or-not. Presuming, if used as per this article, implies we at least have some evidence to support our belief. (I don’t have another funny saying for presume, unfortunately.)

Here's my point in all of this: How often do I evaluate my assumptions and presumptions? Do I even know which is which most of the time? These are useful questions, and I encourage you to give them a try.

For many things in commercial motor vehicle safety, we’ll never have proof. We can’t say with complete certainty that any particular safety management system, safety technology or regulation is effective. So, if we believe something is effective, we’re either assuming or presuming that to be the case. To prove a regulation will have its desired effect is, I presume, impossible, given all the different variables at play and the inability of anyone to conduct a study so perfect that it could actually prove it. Remember, when I say “proof,” I mean PROOF, like how mathematicians can prove 2+2=4.

I’m not trying to be cynical here! Proof is a very challenging standard to reach and, in my honest opinion, really shouldn’t be something about which we’re overly concerned in safety management. We can be effective when we have enough properly interpreted evidence to make good decisions.

In other words, we can presume with great confidence that many things in safety management are effective. Researchers work daily to create or refute evidence that specific safety management elements are effective (and to what degree). The international community of regulators and safety management professionals use these findings to create laws, standards, best practices, devices, training and many other things in good – and evidence-backed – faith.

We do need to be cautious, though. Are we calling something a presumption when it is actually an assumption? If so, we’re accepting something as true without evidence. Evidence is key. Data matters.

This doesn’t mean that every single person involved in commercial motor vehicle safety needs to know and understand the evidence for all the things we presume to be correct. This is impossible. There’s just far too much to know for any single person to grasp.

This is why trust is so important. As a trucker, I had to trust that the laws governing my actions on things like cargo securement and vehicle inspections were effective. How can I possibly be expected to question and challenge everything in trucking safety in a way that’s positive or of value beyond boosting my own ego? I mean, some truckers like to challenge things – this was me at times – but the simple fact of the matter is that, in any role, I am but a small part of a very large and very complex system.

So herein lies the challenge: Effective safety management involves trusting the presumptions of others while ensuring we don’t fall victim to assumptions. If you have any questions, feel free to contact me in my role at the Alberta Motor Transport Association at memberservices@amta.ca; you can also connect with me on LinkedIn. You can presume I’ll get back to you!