LSAT Discussion Forum

When you diagram this statement why do the arrows go in different directions?

Animals that possess horns or antlers use them not to attack prey but for interspecies combat. In fact, animals so equipped never have the claws or fangs that are possessed by predators. Thus, any animal that fights with members of its own species is not a predator.

Reference: #8 page (8-10) from lesson 8

The arrows go in opposite directions because having horns/antlers is a sufficient condition for two separate necessary conditions: intraspecies combat and not being a predator (predators possess claws and fangs, whereas the animals with horns and antlers do not). The premise relationship can therefore be summarized as follows:

Horns/Antlers --> Intraspecies combat

Horns/Antlers --> NO claws/fangs --> NOT predator

Connecting both conditions yields the following diagram:

Intraspecies combat <--- Horns/Antlers ---> NO claws/fangs --> NOT predator

We are looking for premises that can be connected in a chain sharing a common condition (necessary for another condition and sufficient for a third, such as "spot trends" in the stimulus). This answer choice fails the Premise test and is therefore incorrect.

On a side note, we can't quote LSAT questions verbatim, as this is against LSAC copyright regulations! To let us know what question you are asking about, simply identify the question by its location in a practice test or its page number in the homework. Thanks!

Thanks for the explanation! Sorry about that.

Because having horns/antlers is a sufficient condition for two separate necessary conditions: intraspecies combat and not being a predator (predators possess claws and fangs, whereas the animals with horns and antlers do not).