## SCIE 326 - Unit 9 Notes

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By Xing Li July 17, 2019 - 11:46am

# Unit 9

3 principles: non-contradiction, sufficient reason(everything has a reason: logically, empirically, optimally), identity of indiscernible (depending on the hierarchy level of categories)

4 polarities: (in cycle)

 Approach to systems Inference method Reasoning process Form of explanation Top-down Deduction Analysis Functional Bottom-up Induction/ Abduction Synthesis Structural

3 Aristotelian logic laws: identity, contradiction, excluded middle; foundation of truth table

deductive(syllogism), inductive (major <->conclusion), abductive(minor<->conclusion)

Distribution of terms in categorical propositions

 Affirmative Negative Universal SS is distributed PP is undistributed SS is distributed PP is distributed Particular SS is undistributed PP is undistributed SS is undistributed PP is distributed

Figure 9.2.1 (A = UA, E=UN, I=PA, O=PN)

contradictory(P vs Not P), contrary(All vs None)

subcontrary (Some are vs Some aren’t), subalternation (all vs some, none vs some aren’t)

Table 9.2.3

each row is logically equivalent

Table 9.2.4

Table 9.2.5

6 general rules of syllogisms

fallacy of equivocation (four terms), undistributed middle, illicit major/minor, exclusive premises (two negative premises), negative -> negative