Assume “If P then Q.” Four possible moves are:
1. P; therefore Q — valid.
2. Not Q; therefore not P — valid.
3. Q; therefore P — not generally valid.
4. Not P; therefore not Q — not generally valid.
For the invalid forms, consider an alternative way Q could occur.
Opening interactive controls...
Four moves with a conditional
Types of Qiyas: Istithna’i and Iqtirani
Assume “If P then Q.” Four possible moves are:
1. P; therefore Q — valid.
2. Not Q; therefore not P — valid.
3. Q; therefore P — not generally valid.
4. Not P; therefore not Q — not generally valid.
For the invalid forms, consider an alternative way Q could occur.