What is Causality?

As mentioned before, this is abook about LSAT logic, not general philosophy.
Therefore, we will not go into an analysis of David Hume’s Inquiry or Mill’s Methods
(both of which address causality) because although those discussions are interesting,
they do not apply to the LSAT.
When examining events, people naturally seek to explain why things happened.
This search often results in cause and effect reasoning, which asserts or denies
that one thing causes another, or that one thing is caused by another. On the
LSAT, cause and effect reasoning appears in many Logical Reasoning
problems, often in the conclusion where the author mistakenly claims that one
event causes another. For example:
Last week IBM announced a quarterly deficit and the stock market
dropped 10 points. Thus, IBM’s announcement must have caused the
drop.
Like the above conclusion, most causal conclusions are flawed because there
can be alternate explanations for the stated relationship: another cause could
account for the effect; a third event could have caused both the stated cause and
effect; the situation may in fact be reversed; the events may be related but not
causally; or the entire occurrence could be the result of chance.
In short, causality occurs when one event is said to make another occur. The
cause is the event that makes the other occur; the effect is the event that follows
from the cause. By definition, the cause must occur before the effect, and the
cause is the “activator” or “ignitor” in the relationship. The effect always
happens at some point in time after the cause.