Logic / Unit 4 Logic 149 short lesson, about 20 seconds
Modus Ponens
Captions available
The idea
If p then q; p; therefore q. Always valid.
In practice
If the check cleared, the order shipped. It cleared. It shipped.
Where people slip
The conclusion cannot be false while the premises are true — that's the guarantee, certified by table.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Something wrong in this lesson? Flag it · Sources for Logic