Right now, as the snow is falling, I’m kind of glad that the sheep were bred a little late. If we’d bred them on time, they would probably be birthing lambs right about now. This happened to us in a previous year – they had lambs on the absolute coldest day and we had to scramble to make everyone warm and safe (and they did fine). This year, we can just hang out inside and see both moms hanging out in the barn taking it easy.
We have 2 ewes (female sheep) that are both pregnant. If they both have twins (2 lambs each), then we would have 2 ewes and 4 lambs for a total of 6 animals in all. Now, here is a question for you … can you say that is true? Take a minute to think about it, look up pictures of lambs (warning, you’ll be gone awhile because they are awfully cute). The answer is that you should be able to say my statement is true. But why?
You required no other knowledge and could affirm the truth of my statement alone. If I have 2 animals, that each give birth to two animals then that is 2 + 2 + 2, or 6. Congratulations. Take a bow. No really, go ahead, this is worth it. You have just used a priori reasoning. This strange Latin term translates to from before. What it means is that you required no other experiences or evidences or proof to know that something is true. You do not need to own sheep, have raised sheep or ever even seen one. All you need is to understand the words and the numbers. Math is always considered a priori because proving it true requires no other knowledge, other than that of the math itself.
Now, let’s contrast this with a different statement. What if I tell you My sheep are currently sleeping in the barn? Can you prove that is true? While it is possible, you would have to find them and observe them to confirm that they are, indeed, sleeping in the barn and not acting stupid running around in the snow (which they’ve been known to do). If you did this, you would have demonstrated a posteriori reasoning. Also, from Latin it translates to from later. Bet you didn’t see that coming! A posteriori reasoning requires some amount of experiential knowledge to prove a proposition is true. If you’ve ever been on a jury in a courtroom you saw a lot of a posteriori reasoning. During much of our day to day lives we use a posteriori reasoning as we often need other knowledge to validate claims. The snow caused a 2-hour school delay, I’m running low on coffee, New York is the most populous city in the US – all these claims require more outside knowledge to prove them true.
I can hear what you’re thinking right now. Steve, this seems rather pedantic. What practical use is any of this? Truth be told, it is a bit college-philosophy-course-y. However, these two types of reasoning make up the foundation of all reasoning. Understanding these two gives you a foundation to understand other types of logic such as: deductive, inductive and abductive. You can also look at a claim and determine if it is a priori or a posteriori. Once you know that, you can more easily determine what is required to confirm the truth of the claim. I like to say If you need to go to Google, then it’s probably a posteriori.
Ok, we went a little educational today without a lot of real-world connections. In future posts, we’ll see how these two types of logic are the building blocks of reasoning. Our goal as critical thinkers isn’t just to know logical fallacies or how to refute claims. We also want to study metacognition – which is essentially ‘thinking about thinking’. Knowing the basics of logic, how we think, where our errors and blind spots are, will lead us to become better critical thinkers. Besides, who doesn’t like to pull out some big Latin terms to sound extra smart?