The converse of the I proposition, "Some Englishmen are Scotch
drinkers" is "Some Scotch drinkers are Englishmen"--another way
of saying the same thing. If the first proposition is true, the
second must be true, and vice versa.
The converse of "No women have been U.S. presidents" is "No U.S.
presidents have been women." Once again, the statements are
It is not legitimate to take the converse of an A proposition.
The converse of "All pickpockets are criminals" would be "All
criminals are pickpockets." As you can see, the converse here is
not equivalent--the first proposition is true, but its converse
Finally, let's look at the O proposition. An O proposition is
not logically equivalent to its converse. "Some human beings are
not Americans" does not imply "Some Americans are not human