Use Logic to Win Arguments: A Primer for Attorneys
Arguments are the first instruments of our commerce and we can’t use them successfully until we perceive and obey the principles of logic. Regardless of their import, most college students do not need a possibility to review the rules of logic in regulation college. I discover this tragic and consider that logic must be a required course for all regulation college students.
Within the meantime, attorneys and regulation college students should take it upon themselves to be taught the rules of logic essential to craft persuasive arguments. On this submit, I supply a fundamental primer on three instruments of logic which are notably essential within the observe of regulation: deductive reasoning, inductive reasoning by generalization, and inductive reasoning by analogy.
I extremely suggest that each one Lawyerist readers take a look at Choose Ruggero Aldisert’s glorious guide Logic for Attorneys : A Information to Clear Authorized Pondering. For those who don’t have the time or inclination to learn a whole guide on the topic, Choose Aldisert additionally co-authored the article Logic for Legislation College students: The way to Assume Like a Lawyer, which is nice studying for attorneys and college students alike. The next primer summarizes the important thing factors in Choose Aldisert’s article.
In deductive reasoning, a conclusion is compelled by identified details. Deduction is usually expressed within the type of a syllogism, wherein a conclusion is inferred from two identified premises. Probably the most ubiquitous syllogism is:
All males are mortal.Socrates is a person.Subsequently Socrates is mortal.
First you’ve gotten the key premise, which is often a broad and customarily relevant fact; right here, that each one males are mortal. Then you’ve gotten the minor premise, which is often a extra particular and narrowly relevant truth; right here, that Socrates is a person. And the conclusion is true as a consequence of the premises; right here, that Socrates is mortal.
The precept behind a syllogism is that what’s true of the common can be true of the precise. In deductive reasoning, you purpose from the overall to the actual, so it’s important that the overall assertion is a common fact. Think about the next flawed syllogism:
Some males are tall.Socrates is a person.Subsequently Socrates is tall.
The assertion, “some males are tall” doesn’t help you deduct that if Socrates is a person, then he should be tall. Sadly, authorized writing is replete with flawed syllogisms. Don’t anchor your personal arguments in flawed syllogisms. And use your data of logic to reveal the flawed syllogisms within the arguments of opposing counsel. Phrases to look at for embrace: some, sure, a, one, this, that, generally, many, often, as soon as or someplace.
To underscore the significance of deductive reasoning in regulation, Choose Aldisert outlines syllogisms from a number of watershed Supreme Court docket opinions, together with the next syllogism from Marbury v. Madison:
The Judicial Division’s province and obligation is to say what the regulation is.The Supreme Court docket is the Judicial Division.The Supreme Court docket’s province and obligation is to say what the regulation is.
Legislation college students ought to determine syllogisms when studying circumstances and use syllogisms of their outlines and on exams. Word that you’ll typically need to rearrange sentences to find the syllogisms in circumstances or different texts. And generally, solely a part of the syllogism will really be expressed. Writers typically omit components of a syllogism, reminiscent of when a premise is apparent. Casual syllogisms in which there’s an unspoken premise are often called enthymemes. Furthermore, authorized arguments typically encompass a number of syllogisms which construct on each other, often called polysyllogisms. Right here is an instance:
All males are mortal. Socrates is a person. Subsequently Socrates is mortal.All mortals die. Socrates is mortal. Subsequently Socrates can die.Individuals who can die should not gods. Socrates can die. Subsequently Socrates isn’t a god.
As attorneys, we must always make sure that all deductive arguments in our briefs and memos are supported by sound syllogisms. The Choose provides the next generic mannequin, utilized by prosecutors in legal circumstances, as a place to begin to create your personal syllogisms:
[Doing something] [violates the law.][The defendant] [did something.][Therefore the defendant] [violated the law.]
Syllogisms are instruments that can assist you consider and tighten your authorized evaluation. They’re helpful in outlining your arguments or deconstructing the arguments of others. However to be logically sound, your arguments don’t must be expressed by way of syllogisms. The reality of a premise could also be so apparent that writing the premise would make your writing tedious, notably on condition that we write for classy audiences.
Inductive Reasoning by Generalization
If you can’t depend on universals or settled regulation to supply a serious premise to compel your conclusion, you’ll want to construct your personal main premise by way of inductive reasoning. Inductive reasoning by generalization makes use of a number of particular details to create a idea that explains relationships between these details and helps your conclusion. The Choose provides the next instance:
Plato was a person and Plato was mortal.Julius Caeser was a person and Julius Caeser was mortal.George Washington was a person and George Washington was mortal.John Marshall was a person and John Marshall was mortal.Ronald Reagan is a person and Ronald Reagan is mortal.Subsequently, all males are mortal.
To make use of inductive reasoning efficiently, you’ll want to make sure that your supporting details symbolize an acceptable pattern measurement and are consultant. With inductive reasoning, you may by no means be sure that your conclusion is true, however by way of your supporting details, it is best to be capable of set up that your conclusion is very possible.
Inductive Reasoning by Analogy
One other type of inductive reasoning frequent in regulation is analogy, wherein you make one-to-one comparisons and draw similarities between two various things. Somewhat than reasoning from the overall to the precise (deductive reasoning) or from the precise to the overall (generalizations), analogy requires reasoning from the precise to the precise.
Analogy is a standard a part of on a regular basis life and authorized observe. As an example, I’m a lawyer and I discover Lawyerist to be helpful to my observe, so I assume different attorneys will discover Lawyerist helpful to their observe, as properly. The Choose provides the next system for an analogy:
A has attribute Y.B has attribute Y.A additionally has attribute Z.As a result of A and B each have attribute Y, we conclude that B additionally shares attribute Z.
To make use of analogy in regulation, the Choose suggests that you just (1) set up similarities between two circumstances; (2) announce the rule of regulation embedded within the first case; and (three) apply the rule of regulation to the second case. Profitable analogy depends upon the relevancy of the comparability. It’s subsequently essential to element the similarities between the circumstances and to acknowledge their variations. It’s essential to set up that the related similarities outweigh the related variations and subsequently the outcomes must be the identical.
Final up to date August 19th, 2019.