I without this fact does the harm happen b proof of

i. Without this fact, does the harm happen?
b. Proof of causation
i. Substantial factor (“SF”) in bringing about the harm ( Perkins —train going 37 not
substantial factor)
I. Suspicion or speculation not enough to prove SF ( Gentry —gun fired after tripping)
II. Co-existence not enough for SF, must be more likely than not ( Kramer —cut in forehead
and cancer)
III. Reduction in the probability of survival is enough for SF (“loss of chance”) ( Herskovits
—14% reduction in chances of survival)
IV. Possibility harm would have happened without Δ’s negligence doesn’t defeat SF
( Reynolds —fat woman falling down stairs)
V. If you more than double the risk of something, it becomes a substantial factor ( Daubert —
Bendectin birth defects)—“could possibly” does not equal “more likely than not”
1. The more likely than not rule has an inherent problem with being either over or
under-inclusive
ii. Expert Testimony (gatekeeper method determined by court, not jury)
I. Whether derived from the scientific method/reflects good science
II. Peer reviewed and publication (not being peer reviewed is not fatal)
III. Study done independently of litigation (not commissioned for the trial) (not fatal)
IV. Testimony relevant to the task at hand
c. Concurrent causes
i. General rule
I. Where separate acts of negligence combine to cause a single injury, each tortfeasor
responsible for the entire result (joint and several liability), even though his act alone
might not have caused it ( Hill —woman hits truck left in the middle of the road)
II. The concurrent cause made by the Δ must still be a SF in the harm
ii. Elements:
I. Π can’t know who caused the injury ( Anderson —two fires)
II. All possible Δs must be before the court
d. Problems in determining which party caused the harm
i. Burden shifts to Δs to figure out who really caused the harm ( Summers —getting shot)
ii. Even with no concert of action, there can be joint and several liability
e. Market share liability ( Sindell —90% of the DES market)
i. Not all Δs have to be before the court, just a “substantial?” part of the market
ii. Δs are liable for their share of the market (several liability)
iii. Has been limited to DES cases
iv. Expands enterprise liability, where the actors must be in concert (with some sort of trade
agreement)
2. Proximate Cause
a. “Foreseeable” consequence s—natural, ordinary and foreseeable (not unexpected or unnatural)
i. Least to most expansive interpretations
Ryan court Only first adjoining landowner recovers (immediate harm)
Ryan legislature Adds next adjoining landowner
Palsgraf (Cardozo) Must be reasonably foreseeable plaintiff injured (zone of danger)
Wagon Mound I Liability of fire is foreseeability of fire (circle of reasonable
foreseeability; foresee the actual harm)
Wagon Mound II Harm must be “foreseeable enough”
Palsgraf (Andrews) Duty to one is duty to all; very large zone of danger
Polemis If you foresee any damage, you are liable for all damage (property)