Chapter 4 (Underlying assumptions)
Underlying assumption: logical link that fills the gap between the evidence and the claim.
Argument is not acceptable if the underlying assumptions are questionable.
Underlying assumptions are generally implicit (understood / unspoken) as appose to explicit
Once a person’s assumptions about a certain topic are formed, they are the foundation of
everything they think, say and do. They are deeply ingrained and taken for granted. It is rare
that a person will think consciously of the assumption. Part of their tacit belief system.
Tacit knowledge: knowledge you are not aware you have (bike riding example)
How to find underlying assumptions
Evaluate the gap between the evidence and the claim.
1. What must be true if the claim is to follow from this evidence
2. What general principal might link this particular claim to this particular evidence
3. What beliefs might one expect from this person (the author)
4. Could someone believe the evidence but still disagree with the claim? If so, why?
Reality assumptions: are our beliefs about what events have taken place, what exists, or how
things work in the world (our beliefs about reality). They are shaped from firsthand experience,
our conversations with other, and the things we read or see.
Challenging reality assumptions
Evaluate the accuracy of the reality assumptions and critique the quality of the assumptions.
Provide data that would show that the assumption is incorrect. To challenge a reality assumption, we must