A hard word to say, but not that hard to understand. It sounds like a disease to me, I hope it’s not contagious. According to Merriam-Webster, Presupposition: is to suppose beforehand or to require as an antecedent in logic or fact. Using it in a sentence, I might say; “Before you read my blog, my presupposition is that you like to learn about apologetics.” or “It is a presupposition that you don’t have a problem seeing blood if you are going to be nurse.”
In apologetics there are many presuppositions that both sides have when it comes to debates and conversations. For example as a Christian after I have examined and study the Bible, I have a presupposition that the Bible is inspired by God and that it is trustworthy and valid. I have a presupposition that miracles are possible and that God exists. Someone else who takes an atheist position might have a presupposition that there is nothing within our universe that is not physical.
Presuppositions are often foundations that we set at the base of our knowledge and can add-on to our beliefs on top of our presuppositions. Most of the time if a person has a presupposition, they have locked in their trust or belief in that presupposition and it is hard to move them away from what they have already come to find true for themselves.
However, if you really want to “put a pebble in someone else’s shoe” to make them think about their beliefs and worldview attacking their presuppositions are a great way to make some progress. For example, if I were talking with a Mormon and I wanted them to see that Christianity is the one true worldview a good place to start would be to show the Mormon the faults, contradictions, and failed prophecies within the Book of Mormon and it’s leaders through history. If I can show them that the book that they presuppose is true is false, then I have made significant progress in knocking down the pillars that support their Mormon worldview.
As I mentioned before that often times, someone will assume something is true based on their presupposition about a certain related subject, even without knowing that something in an absolute certainty. I might read a difficult passage of scripture in the Bible, but because I have found the Bible to be trustworthy and reliable as a whole, I will take it for truth even if I can’t explain or understand it yet. Both Christians and atheists alike must be careful not to let the cart come before horse in the formulating of their premise and conclusions based on their presuppositions. You can quickly get into circular reasoning, which is a bad debate technique.
If you have any questions, comments, or examples you want to share, please feel free to leave comments.