A book that caused a sensation in academia and the public immediately after its publication!
Logical thinking skills taught by top communication experts!

Tom Peters, known as the 'founder of modern management,' called the management consulting firm McKinsey & Company 'the world's greatest knowledge merchant.'
McKinsey is known as a place where top talent possesses outstanding business knowledge, while also being able to appropriately convey that knowledge and achieve desired results.
Hanako Teruya and Keiko Okada, who wrote “Logical Thinking,” are communication experts from McKinsey.
Logical and understandable messages have certain rules and points, regardless of the field or topic.
The 'Logical Thinking' introduced in this book is a systematization of the logical laws of messages and employee training techniques accumulated by McKinsey.


In particular, 『Logical Thinking』 was designed to help us personally check and improve the expression and logic of the documents we write or speak.
These abilities are essential for not only businesspeople but also students and the general public to succeed in social life and interpersonal relationships in an environment that is constantly changing.
Logical thinking is a 'skill', so anyone can acquire it with enough training.
"Logical Thinking" immediately created a sensation among both academics and the general public upon its publication, reaching number one in the business and management book category on Amazon Japan and selling 300,000 copies.
It also became a bestseller in Korea in 2002, and has been republished this time after rectifying the shortcomings of the original and undergoing expert review.

Mr. A, the branch manager of a certain travel agency, gave instructions in front of all managers at every inquiry.
However, while some departments immediately carried out their work as instructed, there were also departments that did not do anything even after a day or two had passed.
Moreover, both departments reacted to everything in the same way.
Mr. A was curious and worried about why this difference occurred.
To resolve the request, I personally participated in the agency's inquiry.
But, surprisingly, Mr. A always makes comments that can cause the other person to respond differently depending on the situation.
“This week is the busiest time due to the Golden Week holiday, but confirming customer reservations depends on the situation…”

--- From "Chapter 1: Conveying to the Other Party"

When discussing new customer acquisition, it is clearly unreasonable to bring up a company with which C has previously done business, even though it has no current business with the company.
However, meeting attendees who hear this may be deeply convinced by the attractive language of investment efficiency and effectiveness.
So, the direction of the discussion may even change to whether to prioritize new customer acquisition or revitalization of dormant customers.
If you were the boss, it would be right to firmly reject this suggestion.
“You know, we concluded at the last meeting that we needed to develop new customers for these and other reasons.
“You are saying that we cannot discuss existing business partners in the same market as Systema and Satellite,” and you should reject it.
--- From "Chapter 2 Common Flaws in Unconvincing Answers"

Even if you're not a master of the topic or field itself, there are techniques to ensure that your story is free of serious duplication or omissions so that the other person can naturally understand the conclusion you want to convey.
This is a technique called MECE, used by the management consulting firm McKinsey & Company. MECE stands for Mutually Exclusive and Collectively Exhaustive.
This means 'recognizing a thing or concept as a complete, non-overlapping, and complete set of parts.'
It is easy to understand if you think of the concept of a set as dividing the entire set into subsets with no duplicates or omissions.

--- From “Chapter 3: Preventing Duplication, Omission, and Confusion”

Among middle managers, there are many who lament, “My subordinates don’t understand what I’m saying,” or “My subordinates lack comprehension.”
However, the more these people are, the more likely they are to simply relay the instructions given by their superiors to their subordinates, and are unable to say "So What?" in their own words, or to give instructions without a "Why So?"
In contrast, most people in organizations who are evaluated as having quick comprehension skills excel at "So What?", such as quickly and accurately extracting conclusions and important key points from reading materials or listening to others.
Middle managers play a significant role in determining an organization's communication capabilities because they serve as a link between information within the organization.
Therefore, it is essential for middle managers to develop the So What?/Why So? ability.

--- From "Chapter 4: Eliminating Leaps in the Story"

Why do we construct a logical structure? It's obvious: to convey the answer to the task set between you and the other person, ensuring they understand your conclusion and respond as expected.
To achieve the purpose of communication, it is assumed that the conclusion, which is the core of the answer, must be a summary of the answer to the question.
When constructing a logical structure, you must first check whether the conclusion, which is the culmination of the logical structure, is appropriate for the task.
Even when organizing reports or preparing presentations, the task may be 'What is the current status of Business X?', but it is unimaginable how many people later conclude that 'There is a problem with the partnership between the sales and development departments led by Business X, so we need to come up with a strengthening measure.'
Of course, this conclusion deviates from the answer to the question.
--- From "Chapter 5: Creating Logic with So What?/Why So? and MECE"

I once told this experience to a loan officer at a financial institution.
But I heard that person say, “How much easier would it be if you could honestly state the criteria for a loan when rejecting a customer’s loan application?”
But is that really true? From a customer's perspective, wouldn't it be better to hear the criteria honestly, as it might be more convincing and allow them to respond more realistically, such as by exploring alternative options beyond bank loans.
Moreover, the overwhelming information gap that once existed between buyers and sellers, or between beneficiaries and providers of medical services, such as customers and businesses, is rapidly narrowing thanks to innovations in information and communication technologies, symbolized by the Internet.
In the future, customers and service recipients will have access to significant amounts of information, both quantitative and qualitative, and will be able to organize that information themselves.
Then, even the other party who reluctantly accepted something despite feeling unsure will no longer accept it unless a clear standard is presented.
--- From "Chapter 6: Learning Logical Types"

In the case of an explanatory logic type that supports the conclusion in the flow of 'facts → judgment criteria → judgment content', it is persuasive only when the judgment criteria are valid from the other party's perspective.
However, the conversation between the child and the grandmother does not provide any basis for why children must be in the fourth grade to play games.
If the grandmother clearly explains the criteria for judgment, the child will understand.
The essence is the same in business.
If you don't provide a rationale for why you set these criteria when deciding which strategy to choose from among several options or whether to invest in a business, the other party won't accept your conclusion.
One time, I was conducting a logical communication training session for executives at a certain company. At the time, someone said, “How do we set the criteria for judgment? That logic is the very basis of management decision-making.”
That's absolutely true.

--- From "Chapter 7: Using Logical Types"