12 ideas
| 9540 | A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0 [Hughes/Cresswell] |
| 9541 | The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell] |
| 9543 | The rules preserve validity from the axioms, so no thesis negates any other thesis [Hughes/Cresswell] |
| 9544 | A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell] |
| 4045 | Children may have three innate principles which enable them to learn to count [Goldman] |
| 4044 | Rat behaviour reveals a considerable ability to count [Goldman] |
| 4048 | Infant brains appear to have inbuilt ontological categories [Goldman] |
| 4043 | Elephants can be correctly identified from as few as three primitive shapes [Goldman] |
| 4049 | The way in which colour experiences are evoked is physically odd and unpredictable [Goldman] |
| 4047 | Gestalt psychology proposes inbuilt proximity, similarity, smoothness and closure principles [Goldman] |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |