Assumption Question - Supporter and Defender

[lsaths]

On page 331 of LR bible, the side note says,
"If there is no obvious weakness in the argument and you are faced with an Assumption question, expect to see a Defender answer choice."

I am confused with this statement, since Defender question is what is supposed to eliminate a weakness in the argument, and there should be an obvious weakness in the stimuli to do so.

If there is no obvious weakness in the argument, wouldn't it be a Supporter question, which the test taker is aiming to solely link together new elements?

[Clay Cooper]

Hi lsaths,

Good question - the distinction between supporter and defender assumptions can be tricky.

Remember, first, that you'll never get any points on the LSAT for knowing what an assumption is called (a supporter or defender) - more important (and the reason we use these terms) is knowing what the assumption we seek might look like - whether it will more likely be a predictable, gap-filling supporter, or a less predictable, but no less important defender. Keeping this in mind, we can discuss the practical application of the Bible's advice.

Basically, a supporter will fill in a hole in a weak or incomplete argument, often by linking together new elements, as you mentioned. Very often this takes the form of filling in a step in the argument that the author apparently skipped, or in rebutting an obvious objection to his or her reasoning.

A defender, by contrast, protects an apparently strong argument from an unforeseen or unforeseeable weakness. For instance, if I argued that:

The LA Dodgers are scheduled to play at the St. Louis Cardinals tomorrow night at 7.30, and there is no possibility of rain or snow in St. Louis and therefore someone will win the Cardinals-Dodgers game tomorrow night.

...you might not see an obvious weakness, because there really isn't one. So a supporter assumption is unlikely - the argument seems to need no further support. However, a defender assumption - for example:

The world will not end tonight at midnight.

...could absolutely be a correct answer choice, since it must be true if the argument's conclusion is to be true. Thus this answer choice defends the conclusion against the unforeseen possibility that the world might end tonight at midnight.

Does that help?

[JimP]

Clay, I have a similiar question wrt supporter/defender q's...Should I be able to tell if it is a supporter/defender just by reading the stimulus. Right now only after I have read the answer choices can I start to see if it is a supporter or defender...I hope I'm not getting hung up on trying to define the question vs just answering it??

Jim

[Dave Killoran]

Hi Jim,

That is a good question! The answer is: not necessarily. What you will find is that over time, you develop a sense that suggests certain stimuli will feature certain types of answers. Supporters, in particular, can be easy to expect because they fill a gap in the argument, and gaps tend to be easier to pick out when you are reading. At the same time, some Defenders are easier to anticipate than others. For example, in Clay's superb example above, there's no obvious gap in the Cardinals/Dodgers argument, so I'd suspect a Defender is coming. I wouldn't know precisely what option the test makers would choose (for example, they could have said an earthquake or tornado didn't cause cancellation instead of the world ending), but I'd suspect something in the general Defender direction was coming based on the lack of an obvious gap or hole.

That aside, it's not necessary for you to know for sure if it's a Defender or Supporter after reading, and in some cases you just wouldn't have a strong feeling. You'll get a sense over time as to which it is likely to be, but that just helps you go faster; it's not a requirement, and if you fail to anticipate it, it's not a big deal.

Again, shoutout to Clay here—his initial reply is really good

Please let me know if the above helps. Thanks!

[abhola]

Hi Powerscore Team,

I was revisiting the assumptions chapter and after attempting some questions, I am forming a link between supporter vs defender and sufficient vs necessary assumptions.

In my opinion,

Supporter assumptions = sufficient assumptions
Defender assumptions = necessary assumptions.

Do we have cases where

Supporter assumptions = necessary assumptions
Defender assumptions = sufficient assumptions.

I may be unnecessarily complicating this, so seeking so help in clearing this confusion.

Regards.

[Dave Killoran]

Hi Abhola,

I applaud you for thinking about these concepts and trying to piece them together in this way At the same time, I don't want to venture into this discussion because you are mixing language and terms that we work really hard to keep separate because they are generally not well-understood by most students (at least initially), and the last thing I want to do is start introducing relationships that are inaccurate as the basis for a conversation. For example, this phrase--"Supporter assumptions = sufficient assumptions"--is never how I describe it because you are literally saying an actually necessary assumption is a sufficient assumption; it's false to claim that's typically the case. Or, this phrase: "Supporter assumptions = necessary assumptions" is not just sometimes the case, but it's always the case. So you see how the way you are mixing and matching is inherently confusing? My suggestion is to keep reading what I've written about both types of assumptions, as well as when we talked about this in our podcast, and you'll slowly see that we are incredibly careful to not mix terms like this!

The most useful point I can relay to you here is that sufficient assumptions and necessary assumptions can overlap so they are identical; but they do not have to overlap.

Thanks!