A valid inference form in conditional logic: from P → Q and P, conclude Q. Often called "affirming the sufficient": once the sufficient condition is established as true, the necessary condition must also be true. Example: from "If it rains, the ground is wet" and "It is raining," Modus Ponens validly concludes "The ground is wet." Modus Ponens is one of only two valid direct inferences from a conditional (the other is Modus Tollens); the inverse moves — affirming the necessary or denying the sufficient — are formal fallacies.