Most veterinarians, and especially those at university veterinary research centers, have a devoted interest in the bi...

shunhe August 12, 2020

Hi @shamadi,

Thanks for the question! So let’s take a look at what that statement tells us: “among persons who are seriously interested in biological science but lack any special love for animals, one does not find any prominent veterinarians.”

So you might have thought that “any” indicates the sufficient premise here, but take a step back and think about how to word this sentence in “if-then” language or other language that we’ve been using. What does that sentence means? Well, it means that if someone’s seriously interested in biological science but lacks special love for animals, they’re not a prominent veterinarian (or vice versa). Or, in other words, no people interested in biological science but who lack special love for animals are prominent veterinarians. And we know how to diagram both of those statements:

ASIBSLLA —> ~PV
PV —> ~ASIBSILLA

So “ASIBSLLA” isn’t the necessary condition, it’s the negation of ASIBSLLA that’s the necessary condition. You can also make it the sufficient condition, like in the first statement above. And then you would negate “prominent veterinarian” and put it in the necessary. Those two statements are contrapositives, and so are logically equivalent.

Hope this helps! Feel free to ask any other questions that you might have.