Cause and Effect +Defender Assumptions

[Kmikaeli]

For cause and effect, I understand that when a basic causal conclusion is established, the author assumes that the cause is the only cause that permits the effect to occur and thus we use the 5 different methods to weaken such a flawed assumption. However, what if within the premises there is one event occurring before another, does the author assume that the initial event caused the latter event to occur when he/she states such a causal relationship in the conclusion? In other words, if the premise begins with one event that occurs before another, and then the conclusion states that the initial event caused the latter event to occur, then does the author assume that the stated cause is the only cause that allows the event to occur and thus we use the 5 different methods to weaken the argument? If that is the cause, then when does the basic causal conclusion flaw play a role in such a case.


Secondly, within the logical reasoning book the defender assumptions tend to be those answer choices that eliminate an idea that will undermine/weaken the argument. So, when dealing with conditional statements in the conclusion, a defender assumption constituting as one that eliminates an alternative necessary condition? Does another defender assumption consist of 2 of the 5 methods of weakening a causal conclusion, which are eliminating the possibility of an alternative cause and eliminating the possibility of relationship reversal?

[Nikki Siclunov]

Hi kmikaeli,

Let me unpack these questions.

... what if within the premises there is one event occurring before another, does the author assume that the initial event caused the latter event to occur when he/she states such a causal relationship in the conclusion?

If the author states such a causal relationship in the conclusion, I don't see why you'd qualify this as an assumption: it IS the conclusion. Clearly, a temporal sequence of events could suggest a cause/effect relationship, but certainly does not prove that such a relationship actually exists. We can weaken such a conclusion in a variety of ways, as you pointed out.

Secondly, within the logical reasoning book the defender assumptions tend to be those answer choices that eliminate an idea that will undermine/weaken the argument. So, when dealing with conditional statements in the conclusion, a defender assumption constituting as one that eliminates an alternative necessary condition? Does another defender assumption consist of 2 of the 5 methods of weakening a causal conclusion, which are eliminating the possibility of an alternative cause and eliminating the possibility of relationship reversal?

The only way to weaken a conclusion containing conditional reasoning is to show that the necessary condition is actually not necessary for the sufficient. Technically, to defend a conditional conclusion we need to rule out any such a possibility. I must say, however, that assumption questions rarely appear in purely conditional stimuli: conditional reasoning is airtight, and if the argument is valid there wouldn't be any unstated/unwarranted assumptions (an argument such as "A B, B C, therefore A C" has no unwarranted assumptions, for instance).

If an Assumption question follows a stimulus containing conditional reasoning, there are probably also elements of causation in the argument. In fact, the assumption made by the LSAT in logical reasoning stimuli containing causation is that that there is only one cause for each effect. This assumption effectively merges causality and conditionality, casting the cause as a necessary condition. In other words, if we see the effect, then we now the cause must have been occurred. In conditional terms, we can weaken this line of reasoning by showing that the cause is not necessary for the effect to occur; in causal terms, we want to show that there could be alternative causes for the observed effect. It's the same process, from two different perspectives.

Check out this blog post by my colleague Ron Gore for a more in-depth discussion of causal and conditional reasoning:

http://blog.powerscore.com/lsat/histori ... d-the-lsat

Thanks!