In the book Thinking Like a Lawyer, Frederick Schauer provides a good explanation of the distinction between law and fact. In general, 'fact' is understanding and establishing what happened and 'law' is what we ought to do about it.
[Legal reasoning tends to] assume that the interesting issues in Donoghue v. Stevenson' are about whether Mrs. Donohue ought to be able to recover against the ginger beer bottler despite the absence of privity, and mostly ignore the question of whether it really was a decomposed snail that came out of the bottle or just how ill, if at all, the sight of the snail actually made her."
We know after Raffles v. Wichelhaus that when both of two contracting parties are fundamentally mistaken about the object of the contract, there is no contract at all, but how do we know that there were two ships named Peerless, and how do we know that each of the parties really was mistaken?
Below is a great little example of the distinction between law and fact.
Is a manufacturer (or bottler) directly liable to the consumer when there is a decomposed snail in a ginger beer bottle?
Is there a contract tract when the contracting parties have different beliefs about what they are contracting for?
Is dire necessity a defense to a charge of murder?
Does a separate but nominally equal racially segregated school system violate the Fourteenth Amendment?
Was it a decomposed snail?
Were there two ships named Peerless, or only one, or maybe even three?
How close to death were the shipwrecked sailors?
Do black children get a worse education in an all-black, legally segregated school whose physical facilities and teacher training are the same as those in the all-white schools?
Courts determine both fact and law. Richard D. Friedman in his journal article the Distinction Between Fact and Law, puts it this way. Determining facts is allogous to looking back on history and creating a 'mental film' of the event. Determining law 'is to prescribe the consequences to be attached'.
However, determining fact can be very difficult.
Facts, at least disputed facts, usually cannot be determined to, or nearly to, a certainty; thus, the fact-finding function is to reconstruct in imagination various possible accounts... of reality, assigning a probability to each. And the law-determining function must take this uncertainty into account, prescribing the consequences not simply for a given factual state but for a given distribution of possible factual states.
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