Democrats are all Liberal
Things get more complicated when we look at the word “all” in A propositions. We have already seen that the word “all” is sometimes dropped in every- day conversation, as in “Whales are mammals.” The word “all” can also be moved away from the start of a sentence. “Democrats are all liberal” usually means “All Democrats are liberal,” which is an A proposition. Moreover, other words can be used in place of “all.” Each of the following claims can, in stan- dard contexts, be translated into an A proposition with the form “All S is P“:
Every Republican is conservative.
Any investment is risky.
Anyone who is human is mortal.
Each ant is precious to its mother.
To translate such claims, we sometimes need to construct noun phrases out of adjectives and verbs. These transformations are often straightforward, but sometimes they require ingenuity, and even then they can seem somewhat contorted. For example, both “Only a fool would bungee jump” and “Nobody but a fool would bungee jump” can usually be translated into “All people who bungee jump are fools.” This translation might not seem as natural as the originals, but, since the translation has the A form, it explicitly shows that this claim has the logical properties shared by other A propositions.
With some stretching, it is also possible to translate statements about indi- viduals into categorical form. The standard method is to translate “Socrates is a man” as the A proposition “All things that are Socrates are men.”
