Tables, ostensive definitions, & similar instruments I
shall call rules, in accordance with ordinary usage.
The use of a rule can be explained by a further rule.
22.
21). Consider this
example: We introduce different ways of reading
tables.
Each table consists of two columns of words & pictures, as
above.
In some cases they are to be read horizontally from left to right,
i.e., according to the scheme:
In others according to such schemes as:
Or:
etc.
Schemes of this kind can be adjoined to our tables, as rules for
reading them.
Could not these rules again be explained by further rules?
Certainly.
On the other hand, is a rule incompletely explained if no rule
for its usage has been given?