Idea 68: Always test your assumptions
To assume something is to take it for granted, to accept it as true without proof or as a hypothesis. An assumption is any assertion about reality that is unproved or debatable.
Making an assumption –thinking or supposing as if something is the case – is a useful tool in argument or reasoning. It is the tentative adoption of an idea or interpretation, really for exploratory purposes. A hypothesis is a form of well-founded but tentative assumption. You are not committed to your hypothesis or assumption; you can jump off the bus any time you like.
Much more dangerous both to clear thinking and creative thinking, or to generating new ideas, are the unconscious assumptions ...