If the purpose of an argument is to prove its conclusion, then it is difficult to see the point of falsifiability. For deductive arguments cannot prove their conclusions any more than inductive ones can.
But if the purpose of the argument is to force us to choose, then the point of falsifiability becomes clear.
Deductive arguments force us to question, and to reexamine, and, ultimately, to deny their premises if we want to deny their conclusions. Inductive arguments simply do not.
This the real meaning of Popper’s Logic of Scientific Discovery—and it is the reason, perhaps, why so many readers have misunderstood its title and its intent. The logic of discovery is not the logic of discovering theories, and it is not the logic of discovering that they are true.
Neither deduction nor induction can serve as a logic for that.
The logic of discovery is the logic of discovering our errors. We simply cannot deny the conclusion of a deductive argument without discovering that we were in error about its premises. Modus tollens can help us to do this if we use it to set problems for our theories. But while inductive arguments may persuade or induce us to believe things, they cannot help us discover that we are in error about their premises. [113-4]