We experience the world through patterns—drop a ball, and it falls. Light a fire, and it burns. We think of one thing causing the other as common sense. It’s part of our everyday life. But does that mean cause and effect is certain?

Born in 1711, Scottish philosopher David Hume didn’t think so. He pointed out that just because something always happens in our experience doesn’t mean it must happen. We assume the sun will rise tomorrow because it always has—but that assumption is based on habit, not certainty. Could an unseen factor be driving both? This is the essence of the causation versus correlation debate.

However, Hume was also a pragmatic man and he didn’t debate the rising of the Sun everytime someone mentioned it. He simply challenges us to add doubt where needed. In chapter 27 of 30 Philosophers, I demonstrate this with a simple shift in language. I change the statement “All swans are white,” to “All known swans in Europe are white.” This clearly demonstrates how Hume is asking us to be more nuanced with our language.  

Instead of assuming cause and effect as absolute, critical thinkers add nuance by demanding evidence, using logic, and adding appropriate qualifiers. So next time you hear “X causes Y,” pause. Ask as Hume would: Is this a certainty, or just a strong habit of thought?

In the TST Framework, exploring cause and effect falls under Logical Analysis and Evidence-Based Reasoning, challenging assumptions about causation and requiring scrutiny of whether observed patterns indicate certainty or mere correlation. It also ties into the Mind Trap of Assumption, where people mistake repeated events for causal relationships without verifying underlying mechanisms. Good critical thinkers try to add the needed doubt especially with statements of cause and effect.