23 ideas
13070 | If definitions must be general, and general terms can't individuate, then Socrates can't be defined [Aquinas, by Cover/O'Leary-Hawthorne] |
11197 | The definitions expressing identity are used to sort things [Aquinas] |
13913 | The four 'perfect syllogisms' are called Barbara, Celarent, Darii and Ferio [Engelbretsen/Sayward] |
13914 | Syllogistic logic has one rule: what is affirmed/denied of wholes is affirmed/denied of their parts [Engelbretsen/Sayward] |
13915 | Syllogistic can't handle sentences with singular terms, or relational terms, or compound sentences [Engelbretsen/Sayward] |
13916 | Term logic uses expression letters and brackets, and '-' for negative terms, and '+' for compound terms [Engelbretsen/Sayward] |
13850 | In modern logic all formal validity can be characterised syntactically [Engelbretsen/Sayward] |
13849 | Classical logic rests on truth and models, where constructivist logic rests on defence and refutation [Engelbretsen/Sayward] |
13851 | Unlike most other signs, = cannot be eliminated [Engelbretsen/Sayward] |
13852 | Axioms are ω-incomplete if the instances are all derivable, but the universal quantification isn't [Engelbretsen/Sayward] |
11195 | If affirmative propositions express being, we affirm about what is absent [Aquinas] |
11201 | Properties have an incomplete essence, with definitions referring to their subject [Aquinas] |
18431 | Internal relations combine some tropes into a nucleus, which bears the non-essential tropes [Simons, by Edwards] |
11205 | If the form of 'human' contains 'many', Socrates isn't human; if it contains 'one', Socrates is Plato [Aquinas] |
13090 | The principle of diversity for corporeal substances is their matter [Aquinas, by Cover/O'Leary-Hawthorne] |
11202 | It is by having essence that things exist [Aquinas] |
11203 | Specific individual essence is defined by material, and generic essence is defined by form [Aquinas] |
11200 | The definition of a physical object must include the material as well as the form [Aquinas] |
11196 | Essence is something in common between the natures which sort things into categories [Aquinas] |
11208 | A simple substance is its own essence [Aquinas] |
11198 | Definition of essence makes things understandable [Aquinas] |
11206 | The mind constructs complete attributions, based on the unified elements of the real world [Aquinas] |
11207 | A cause can exist without its effect, but the effect cannot exist without its cause [Aquinas] |