In the books of Eli Goldratt you can read very often the term common sense. We have also heard that common sense is not so common. Eli Goldratt and his daughter Efrat Goldratt-Ashlag have spent two chapters in their book “The Choice” on this subject: “Chapter 2: Uncommon Sense” and “Chapter 3: Why is Common Sense Not Common Practice?” Both have claimed in their book, “… cause-and-effect logic is common sense …”
Two questions are popping up now:
1. What is common sense?
2. Is it sufficient to apply cause-and-effect logic to become a good “common sense practitioner”?
1. What is common sense?
If you “google” the term common sense, you can find a number of definitions. I selected only two of them:
• Sound and prudent judgment based on a simple perception of the situation or facts 
• Your common sense is your natural ability to make good judgments and to behave in a practical and sensible way. 
In some languages, the view is that people possess by nature common sense. In German one calls the common sense “Gesunder Menschenverstand” and in French "Sens commun". With the words "Verstand" or "sens", we mean "mind". In addition, the word "common" or "commun" means "all together" - at least, but mainly "frequently" or "widespread". However, the philosopher François-Marie Arouet (1694-1778) - better known under his pseudonym "Voltaire" – made a paradoxical observation:
The term common sense is often used, but seldom applied ("le sens commun est fort rare")
This paradox disappeared when the German philosopher Immanuel Kant (1724-1804) entered the stage. Since that time, we have to make distinctions. He characterized man as an "intelligent animal" and assumed he could "make of himself a right-minded animal." Therefore, Kant thought people had the ability to be reasonable. Nevertheless, he did not think that all people actually exercise that ability.
I think Kant's assessment is quite plausible. Most people have the ability to walk and run, but they cannot run so fast like Usain Bolt (* 1986). Most people own as well as the ability to move her fingers, but they cannot play piano like Lang Lang (* 1982).
If you have a skill, you do not necessarily develop it consequently. The same applies to common sense!
Okay, what can we summarize so far?
Common sense is a human ability we should train. It will lead to reasonable thinking for better judgements in all areas of life.
2. What to do to become a good “common sense practitioner”?
During my investigations to find a useful answer, I found only one book in German language. In 2017, the German Philosopher, Economist, Trainer, Consultant and Author, Nikil Mukerji, published a book titled “Die 10 Gebote des gesunden Menschenverstands”  – “The Ten Commandments of Common Sense”. In my opinion, the author wrote a very comprehensive and easy to understand book about this subject.
Next, I want to share with you his insights which should be useful for everyone.
1st Commandment: Bring order to your thinking
The first commandment prompts you to clear your mind. It requires you to follow your train of thought into individual arguments and the relationships between them. If you do not do that, then you think confused. To mix your thoughts become an "amorphous mush". To aim for that seems hardly reasonable!
2nd commandment: Think completely!
The second commandment asks you to think completely. You do that if you do not close from A to Z, but from A to B, from B to C, and so on, until you finally arrive at Z. To do otherwise would be obvious unreasonable. Because if you think incomplete and skip steps in your thinking, it will increase the probability that you make a mistake.
3rd commandment: Make credible assumptions!
The third commandment requires that the assumptions, on which you build your train of thoughts, are credible. That is important because assumptions have the function to support conclusions and thereby make them credible. This function can only be useful if you are plausible to yourself. To start with implausible assumptions would be rather unreasonable!
4th commandment: Ask for the burden of proof!
The fourth commandment makes it clear that you should not believe anything if you have no good reasons for that. If you do that anyway, then what you believe is a superstition.
That is unreasonable!
5th commandment: Think clearly and precisely!
The fifth commandment demands you to think clearly and precisely. Because only then your thoughts do have a relationship to reality and can help you to solve practical problems.
Nobody should aim for unclear and imprecise thinking.
That would be unreasonable!
6th commandment: Stay logically clean!
The sixth commandment asks you to avoid logical mistakes. These errors may occur, if you have assumptions that are incompatible in itself, or if you draw conclusions without sufficient coverage by your assumptions. Both are obviously unreasonable!
7th commandment: Do not tamper into the speech trap!
The seventh commandment protect you for the perils of language. It requires you to check linguistic
Expressions for ambiguity. If you do not do that, you run the risk of committing misconceptions.
You as a reasonable person should avoid that!
8th Commandment: Be smarter than a young hunting dog!
People say about young hounds that they have some hunting problems to keep track, because they distract easily in cases where strong odors arouse their interest.
The eighth commandment asks you to be smarter than a young hound. If something else is distracting your thoughts, then you should take care that they stick to the matter and are relevant.
Because that would be unreasonable! As Eli Goldratt would say: “Focus!”
9th commandment: Look with both eyes (if you need to)!
Try to avoid overlooking information that is relevant to your question. The information might be important. That tells you the ninth command. Who injures, leaves certain information disregarded, which are relevant to the issue.
Even that would be - you guessed it already - unreasonable!
10th commandment: Do not let someone hoax you!
The tenth commandment is closely related to the fourth. It says that one can only take a position if the reasons for this position are good enough so that the burden of proof, which rests on it, has been actually fulfilled. The Fourth bidding only requires that you recognize when there is a burden of proof. The tenth commandment, on the other hand, says that you can be deceived by reasons that only supposedly fulfill the burden of proof.
An injury of this commandment also leads to an unreasonable Superstition!
Now we know the pillars of common sense that will help us to become a better common sense practitioner, if we start to train this kind of thinking.
TOC Thinking Processes Practitioners should know this entire staff already, because we can find it back in Eli Goldratt’s books. Perhaps with slightly other words, but the core is the same. Nevertheless, Nikil Mukerji added a number of very useful hints, tips and tricks for each commandment in his book.
And what is about the claim “… cause-and-effect logic is common sense …”? Nikil Mukerji has put it in his sixth commandment: Stay logically clean! Of course, he did not mention or explain the Thinking Processes as a practical way to deal with logic, but he described the basics and emphasized the importance of cause-and-effect logic.
 The Choice, Eli Goldratt & Efrat Goldratt-Ashlag
 Die 10 Gebote des gesunden Menschenverstands, Nikil Mukerji