Use the standards of validity and soundness to determine which assumptions can be fairly added
in order to make deductive arguments complete.
You can always make an argument valid by adding a conditional whose antecedent is the
premises and whose consequent is the conclusion.
People have called premises that are not stated but are needed (to make the argument valid and
explain how it works) suppressed premises. An argument depending on suppressed premises is
called an enthymeme and is called enthymematic.
To trace the pathway between premises and conclusion, it is usually necessary to fill in these
suppressed premises that serve as links between the stated premises and the conclusion.
An argument is a single premise which has grown to include three stages with at least four
suppressed premises. We cannot assume that the person who gave the original argument had a
more complete argument in mind (so never assume this).
The proper use of the many suppressed premises are necessary to make the entire argument
sound. Seeing this brings out the assumptions that are seen as true for the conclusion to follow