What is a background assumption? What is meant by background assumption?
A background assumption is something implied or assumed by what you say, but not explicitly stated.
For instance, if you say 'I feel happy'.  It is implied or assumed that you exist.  It is also implied or assumed that happiness exists.  It is implied and assumed that you have feelings.  It is implied that you have told the truth rather than a lie. A background assumption is that you and I both interpret happiness in a similar way.
Many things we say include background or implied assumptions.  Fortunately, most people make similar background assumptions which means that they don't need to be stated, which greatly aids in efficient communication.
Did you notice that I made the assumption that we all make similar background assumptions?
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