Book, Paragraph

 1      I, 21|        21~If one premiss is pure, the other problematic,
 2      I, 21|    will be problematic, not pure; and a syllogism will be
 3      I, 21|    if the proposition BC is pure, AC problematic; or if AC
 4      I, 21|  matter which of the two is pure; in both cases the conclusion
 5      I, 21|    that we shall have not a pure but a problematic syllogistic
 6      I, 22|    both a problematic and a pure negative conclusion are
 7      I, 22|    will be problematic, not pure; and also when one premiss
 8      I, 22|   conclusion also will be a pure negative proposition; for
 9      I, 22| problematic, and when it is pure. It is evident also that
10      I, 24|    also in being necessary, pure, problematic. We must consider
11      I, 29|     whether a possible or a pure proposition is proved. We