In the system of categorical logic, there are four standard-form propositions, and only four. You mean everything
that we can assert can be translated into one of these four forms? That’s right; there are only four kinds of
propositions, only four. Now don’t forget, there are thousands of different propositions, if we differentiate them
in terms of their content, but only four if we distinguish them in terms of their form.
So what are these four standard-form categorical propositions? Well, here they are: