Further data to use with them may be missing or not available. In the middle chapters, the problem of identifying reliable knowledge is described, but not solved, except for an explanation of the empirical method of coping. The identification problem touches many subjects. Students of critical thinking, persuasion, philosophy, mathematics, science and technology should find its discussion helpful. The last chapters in this book show how the common concepts of a rule being obeyed, disobeyed or not disobeyed may justify or explain or provide a context for the entries in truth tables for material implication.
Some symbols appear in the discussion of logic.
The last chapter describes indirect methods for using implication rules to arrive at conclusions - a subject of interest to mathematics students and perhaps readers of detective mysteries. This work equals the first part of the two-part work, Volume 1, Elements of Reason. The second part is provided by Volume 1B, online in the Mathematics Education Revisited area. Elements of Reason - v. 2. Three Skills for algebra - v.3.