Meeting Bill Dettmer

I am fortunate having met William Dettmer in Paris, France, November 27 and 28th, 2014.

Bill is senior partner with Goal Systems International and author of eight books and numerous articles about Theory of Constraints, Thinking Processes and more.

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I have read Bill’s works and found myself deep-diving with great intellectual pleasure into Goal Trees, Current Reality Trees, Conflict Resolution Diagrams and more. It helped me a lot getting familiar with the Thinking Processes.

Having the opportunity to meet, chat and listen to the author in my hometown is a rare privilege I enjoyed very much.

Bill was guest of Philip Marris, the leading authority of Theory of Constraints in France, in his Paris office. Philip invited me too, challenging me with video recording and editing the meeting for an online series of videos.

Hohmann, Dettmer, Mano

These two days were great fun, sometimes for the talents in front of the cameras watching me running around the setup to check, fix or start a device, sometimes for all when the inevitable bloopers forced to restart the take.

While monitoring the recordings, I learnt a lot listening to Bill’s explanations and stories. He is not only an expert with long experience, he’s also a great storyteller.

These last points were endorsed by Erik Mano, the third guest of Marris Consulting, who attended Bill’s course in Luxembourg some time ago and testified about the course, its content and the usage he made of the Thinking Processes.

Dettmer and Hohmann

While these two days were fairly high-density, we found moments to relax. Philip suggested a picture of Bill and me sitting side by side with our books in front of us.

Regarding the number of books, Bill won (8 to 4) but admitted to the fact of being few years younger, I still can catch up.

But what I will never be good at is smiling.

Watch the first video introducing a serie about the Logical Thinking Process

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Frightening slowness in a fast moving world

Usually the high pace of changes and speed of events in our world is frightening and we complain about things going much too fast, stressing our adaptation capabilities.

But as we get used to it, slowness once soothing can now be frightening.

In the last months is 2014 I am facing a change in my professional life, with a thrilling project at hand. This can significantly impact my personal life, career and bring me lot of satisfaction.

Alas, decisions go as slow as the European economy these days. Lots of hesitations and postponements, something never good with projects.

From initial excitement to frustrating waiting, this slowness is somewhat frightening. What if the project finally ends as a nogo?

Beyond my personal case, slowness and hesitations caused and still cause some (consulting) companies to go bankrupt, just because of decisions not taken, projects starts constantly postponed and above all: payments delayed.

When economic condition was better, it was manageable in some extend, however at the expense of margin. Now, clients’ hesitations and slowness are frightening.

Delayed payments for the sake of cash flow at the expense of suppliers remain unfair, as usual.

Isn’t it ironic that we usually grumble about so many things going too fast and suddenly complain about what goes too slow?

For important things, it’s even frightening slowness in a fast moving world.

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What is VSM good for?

Value Stream Mapping (VSM) is one of the most popular tool of the Lean toolbox, frequently associated with finding improvement opportunities. Yet VSM is more than a kind of treasure map.

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Enabling “helicopter view”

Drawing a VSM is like getting aboard a chopper and take off to watch the perimeter or process from some distance and height. I like the helicopter metaphor because we can hover over the Value Stream Map at will, focus on a particular zone, fly over the whole, fly back again and so on.
Taking some distance and height let analysts consider a zone, a part of the process or series of  operations in their global context. Even so VSM is schematic, interactions with up and downstream operations as well as information exchange are more visible than on shop floor.
Conversely, VSM doesn’t show the details and cannot replace investigations in situ.

Physical and information flows

VSM is most probably the sole tool allowing the simultaneous view of physical and information flows as well as their interactions.
VSM can reveal the hidden complexity and abundance of IT systems, softwares and applications, files and databases, often duplicate, redundant and with multiple input points.
Many wastes clutter information flow, more difficult to make out than those of the physical flow. Something the Value Stream Map shows.

Share the findings

VSM is an excellent mean to share the assessment findings with stakeholders.  I could verify it on numerous occasions; operators know well their work post and its immediate surrounding but have little knowledge about what is happening up and downstream. Support departments, especially administrative staff, know very few about operations while ops guys ask themselves what good the administrative staff do.
When working together on a VSM, even only partially, and later during debriefing ,’ all stakeholders share the same ‘picture’ of the actual state, understand  dynamic interactions  and interdependencies between the different links of the whole chain

I could witness people cooling down after understanding why their colleagues kept demanding something bothering. The VSM just made clear why this was important to someone else in the stream. From then on, not only would the irritation disappear, but the angry people change to pro actively help their colleagues, easing the later operations.

Common language

VSM uses symbols (pictograms) and terms which become a common language  between stakeholders. Concepts like flow, Lead Time, Work in Progress or wastes   are understood , even by those remote from shop floor.

When a workgroup is made of several participant without a common tongue – something common in big international corporations with multiple subsidiaries in the whole world, or to consultants assigned to such a subsidiary – thanks to VSM visual symbols, working together with this common language is possible.

Sell one’s ideas

Presenting and debriefing a diagnostic’s results is backed up by a VSM. Together with the future state map, called Value Stream Design (VSD), action plan showing how to get from actual state (VSM) to future state (VSD) it help selling the ideas for a change crafted by the workgroup.

Those receiving the debriefing and proposition, VSM/VSD provide a convenient and useful support to make the whole tangible, concrete.

It happened frequently that our debriefing after assessment was only a standing storytelling in front of a VSM. The whole story is depicted there and it is easy to take the audience in the imaginary helicopter and hover above the process.

A Value Stream Map is therefore a great communication tool.

Revealing wastes

Looking at a process from some distance helps reveal wastes that are not noticeable without zooming out. Duplicate inventories or operations in different locations for instance.
A spaghetti  diagram – natural companion of a VSM – drawn in the same time as the VSM is also an excellent tool / way to reveal wastes like unnecessary transportations, time lost in lengthy walks and motions, routes within the facility, even ‘crowded highways’, etc.

Without VSM’s ability to “zoom out” and consider the process in its whole, most of these wastes would remain hidden.

Decide and coordinate actions

Working together and considering the actual state from some distance greatly helps to take good decisions and coordinate actions which will benefit to the whole instead of trying to optimize locally. This latter way is potentially counterproductive, as interactions and interdependencies do not lead the sum of local optima to a global optimum..

Prevent static figures fooling you

Compared to data / dashboards / KPIs analysis, VSM is more qualitative but depicts the dynamic behavior or a system. Dashboards and reporting are far more static and partial; showing a “frozen picture” of past situations and do not show the dynamics and interdependencies of resources.

VSM is nevertheless completed with figures, indications of actual performance levels or potentials at the moment of mapping. They are benchmarks, either for challenging the actual results or measure progress.


All these advantages and benefits of Value Stream Mapping endorse the place and importance of this tool in the continuous improvement or operational excellence toolbox.
It is probably no surprise for those having experienced Value Stream Mapping, but did they notice all of the advantages?

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Tales from the Pyramid – Base first

Some improvement initiatives start bottom-up, especially in bigger companies or corporations, when a department manager or local executives decide a Lean deployment program launch without a formal go from top-most bosses.

It can also be a pilot workshop in some area, “just to see” the outcome, agreed by top but without much of their involvement.

Unless the top management is convinced about the improvement initiative and is supporting it, the pyramid looks much like the base is moving forward while the top stays put.

These kind of initiatives may start well, whether because the base is willing to improve operations and reap some benefits for its own or is simply executing orders.

The head of the organization may remain unaware or uninterested for a while or let the thing start without endorsing it, for some reason.

Such a base-first initiative is not likely to succeed as chances are:

  • The champions leave
  • Priorities change
  • Successes may be visible on shop floor but do not show on financial reports
  • It looks like the initiative costs a lot (expenses can be counted) but does not yield countable results from corporate point of view
  • Distracting resources from normal occupation may not be agreed after a while
  • The improvement areas or themes make no sense at corporate level
  • Top management may get clearer idea about improvement potentials, but now want them aligned with strategic objectives

Whether it is stopped or realigned, stakeholders will probably resent it and get discouraged to go on. After all, stopping or realigning the initiative is equal to state the efforts were useless (and nobody stopped them from the beginning).

I do not believe in success of bottom-up initiatives and I can’t remember having seen one succeed after a longer period. Some of them may last some time, but sooner or later one of the above mentioned phenomena will bring it to stall.

If you have a success story started bottom-up to share, you’re welcome!

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Conflict Resolution Diagram / Evaporating Cloud

The Conflict Resolution Diagram (CRD), also known as Evaporating Cloud (EC) or simply ‘Cloud’, is a necessity-logic based tool from Theory of ConstraintsThinking Processes.

As the name tells, the Conflict Resolution Diagram is used to surface and resolve conflicts, e.g. dilemmas.

Conflicts, which can be named ‘different points of view’ are not always obvious, thus practitioners will refer to as ‘hidden conflicts’. Indication a hidden conflict exists is stagnation (Dettmer). Two opposite forces pull in opposite directions and nothing goes on.

The CRD is based on two assumptions:

  1. Conflicts (opposition about objectives or opposite points of view, for instance) tend to be settled by compromise. Yet compromising requires making concessions that lead to a solution which isn’t satisfactory for neither side, hence a win-lose or lose-lose situation.
  2. Conflicts are often the result of false assumptions, beliefs or myths which constrain needlessly the organization. As two opposite things cannot be true at the same time, one is necessarily false. If the falseness can be debunked, the conflict disappears (evaporates) and a no-compromise, win-win solution is found.

Resolving the conflict is done by first exposing the two sides’ arguments, second through “injection(s)”; adding something, solution, countermeasure, a “remedy” that didn’t exist in the system.

The structure of a Conflict Resolution Diagram / Evaporating Cloud

A (simple) CRD is made of five entities (round cornered boxes) conventionally named A,B,C,D and D’.

Entity A is the common objective which requires B and C to exist; in order to have A, we must have B and C.

D is a prerequisite to B (in order to have B, we must have D), while D’ is a prerequisite to C.

D and D’ cannot exist or happen simultaneously, like for example attend a meeting in Rome and in the same time attend a conference in Berlin. In this case the conflict would be a dilemma chosing between the two events. D and D’ may not happen simultaneously because available resources do not allow it and the dilemma is about allocation of the scarce resource.

Arrows are symbols of necessity relationship. In the same time the arrows are symbols for underlying assumptions, and as such can be true or false. But the assumptions are usually statements (beliefs) and/or justification for the relationship. The CRD’s purpose is to surface and test these assumptions.

The broken arrow or lightning between D and D’ is the symbol for opposition or conflict.

Surfacing and testing the underlying assumptions and injections

Once the CRD is drawn, participants are asked to verbalize all underlying assumptions under each arrow. If one of the assumption can be proven as false, it is probable that the problem evaporates (we do expect the defenders of the false assumption to give it up as false).

An assumption can also be invalidated by an injection, which are ideas or conditions that render one of the assumptions invalid.

Note: Dettmer recommends not to inject solutions in order not to constrain the injections with reservations about feasibility.

Conflict Resolution Diagram can be used as a stand-alone tool or sequentially after a Current Reality Tree (CRT). In this latter case, the analysis with the CRT helped discover the root cause of all Undesirable Effects (UDEs) usually called problems. This root cause is generally a conflict or dilemma the CRD can ‘evaporate’, thus solve the problems.

Solving a problem with a CRD is a bit more complex than in this brief description and requires some practice.


  • Fedurko, Jelena (2011) Behind the Cloud, enhancing logical thinking, TOC strategic solutions
  • Dettmer, H. W., (1997) Goldratt’s Theory of Constraints: a systems approach to continuous improvement. ASQC Quality Press
  • Scheinkopf, L., (1999) Thinking for a change: putting the TOC thinking processes to use. St Lucie Press/APICS

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Theory of Constraints is something great, except for its name

Theory of Constraints (ToC) is among the three philosophies / approaches / methodologies with Lean and Six Sigma leading to tremendous success, but the only one with two frightening words out of the three of its name!

When facing tough challenge or stuck in a crisis, the last thing anyone would look for is a theory. Instead, people with urgent need for improvement would seek something practical, action-focused and yielding short-term.

Too bad, maybe the only thing that could help in such a case is named “Theory”.

>lisez cet article en français

The same people firefighting with their daily problems feel having more than their share of constraints and again, maybe the only thing that could help them holds “constraints” in its name.

I don’t know what led Eli Goldratt, father of ToC name it that name, but I am quite sure it is an obstacle (a kind of constraint!) to the diffusion and adoption of his teachings.

Fame, despite the name

The problem is that Theory of Constraints is now relatively famous, at least among all those having read ‘the Goal’ and grew a corpus which make a change of name unthinkable.

The same happened with ‘5S’, made of five Japanese words few westerners remember. They keep irritating, but it’s a bad idea to rename them if you want to remain understandable by others.

Same with ‘Lean’, first thought to be a clever way to summarize frugality in operations, but this name got mean meaning over time, with a meaning closer to anorexia thanks to poorly and ill-led implementations. Yet it is too late to change the name.

Newcomers, don’t get frightened by the name!

Newcomers give it a try! Don’t get frightened by the name, Theory of Constraints (ToC) is something great, except for its name, we’ll agree.

Think about much more frightening (and unpronounceable) names of drugs you take and the cure they provide. ToC is like such a remedy, not very good sounding but effective and with only positive side effects!

More on this subject: Bill Dettmer and Philip Marris discuss the point

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Cost and inventory reduction, right target?

Lego_022aWaste and costs reduction has almost become the definition of Lean for many people as well as an irresistible lure for most executives and managers.

Yet costs and inventory reduction, is this the right target?

In the various definitions proposed by Lean theorists, including Jim Womack, priority is given to identifying and creating value for customers. Using just needed resources is only a way to achieve this while seeking a competitive advantage. Reducing costs and make savings is only a corollary effect of this achieved frugality, not a prime objective.

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Why this obsession about waste / costs?

Lean has long been considered being something for operations: Production, Logistics … as its first name “Lean Manufacturing” could suggest. Indeed, first attempts and successes happened in the workshops and warehouses, on shop floor.

Operations guys have little leverage to create value for the customers. Conversely they can improve almost infinitely operations seeking to be more efficient, to speed up the flow or to reduce defects.

These improvements, synonyms of savings, quickly raised management’s interest in order to justify related expense of these initiatives with ROI and reap the “promised” gains.

However, most of the time these approaches do not produce the expected measurable results and generate frustration among actors although they often see dramatic improvements at their level .

Frustrations, failures, how is this possible?

First one must understand that local initiatives are often disconnected from the purpose of the organization / company. They “improve” activities or processes without a prior validation about their system-wide usefulness and contribution to the higher objectives of the organization / company.

The most disappointing case is to have improved a doomed process or one being itself a waste. In such a case, time and resources were consumed in vain. Deadly sin.

In a less extreme but frequent case, time and resources were consumed to improve a marginal process, which will be insignificant to the overall performance, despite the fact it looks spectacular in situ.

Second, one must remember that the cost and/or inventory reductions necessarily face an absolute limit, which is zero. Once there is no more spending and/or any inventory, this is the end of “continuous” improvement and ironically… an optimum.

Of course there is a practical limit before zero, from which the activities can not proceed satisfactorily neither for customers nor for other stakeholders. But this practical limit > zero only reduces the overall potential of cost and/or inventory reductions.

In contrast, sales growth is virtually unlimited. Although productive resources are saturated, it is always possible to provide new, additional value added services, such as express delivery, personalization, premium services, etc.

But this lever, far more powerful and faster to implement, contrary to general belief, is rarely used.

What alternatives to achieve success?

Those who embraced Lean Management understand that all improvement efforts must be aligned with the purpose of the organization / company, i.e. the need for improvements is derived from the Goal, strategic objectives and necessary conditions to achieve strategic objectives.

Therefore, Lean is only conceivable top-down, from the strategic intent to shop floor actions. Then, for people to apply coherently tools and methods, instead of locally cherry-picking any good looking idea, top management must dictate the needs to cover or better, communicate in transparent manner strategic intents and the cascade of necessary conditions to achieve high level objectives, thus the Goal.

Once these necessary conditions known, operators can measure the gap between the desired state and the current state and work to reduce this gap, on relevant topics and perimeters.

This communication is done using Hoshin Kanri and A3 reports when remaining in the traditional Lean framework, or using Goal Tree if open to add some Theory of Constraints’ tools.
Both are perfectly combinable.

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Thinking Processes – Current Reality Tree

The Current Reality Tree (CRT) is one of the Thinking Processes logical tools. As the name tells, it depicts the current reality* in a series of dependent logical cause-and-effect relationships, starting from Undesirable Effects down to one or a few critical root causes.

A root cause may also be called “core problem” or “core driver” in the original concept.

*Current Reality is somewhat misleading as it is focused onto the negative outcomes and what prevents achieving the Goal in order to solve problem and improve the situation. Besides, the Current Reality depicted in a CRT is a snapshot at a given moment.

Undesirable Effects (UDEs) are often called “problems” that people perceive, suffer from or have to cope with, but UDEs are most often only symptoms of deeper laying problems. The CRT is a tool that helps to surface and address the critical root cause(s).

As for many elaborated problem solving methods and tools, building a CRT is not required for every problem. It was specifically designed to solve complex, multi-factor and system-wide problems.

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Reading a CRT

It takes some experience to build a robust Current Reality Tree, which should not be done by a single person by the way (for the sake of robustness), and the best is to get used to read them first.

Current Reality TreeA CRT has more or less a V shape with the topmost and numerous UDEs on the top, other UDEs that are causes from topmost UDEs and their own causes, and so on down to the few critical root causes, usually located (near or) on the base of the CRT.

Once a tree is completed, it can be read either top-down or bottom-up. The construction is always top-down, from symptoms to causes to critical root causes.

A CRT is made of entities which are round-cornered boxes holding a brief description of a fact in present tense. Entities are either causes or consequences and most of them are both.

Entities which are linked have an arrow between them. The base of the arrow reads “if…” and the tip reads “then…”.

When reading a CRT top-down, the succession of linked entities reads “entity B exists (tip of arrow points to it) because of entity A (arrow starts from it)”.

When two or more arrows point to an entity, the entities at the base of the arrows are possible causes. The different arrows are logical “inclusive OR” relationships.

When the arrows are encircled by an ellipse, it means logical “AND” relationship: all the causes must exist simultaneously for the effect to exist.

Theory of Constraints is about focusing and leveraging, so does the CRT. The purpose of a CRT is to search for the root cause and while eliminating it, the whole tree of dependent UDEs disappears.

The investment of analyzing the situation with a CRT is really worth it, compared to the useless and wasted efforts trying to solve all the UDEs. Concentrating efforts on the sole critical root causes is much more efficient.

CRT example

CRTHere is one half fictitious example of a CRT inspired by a company I worked with.

The V shape is not so obvious (due to page / screen width limitation) but even without reading the entities, you’ll notice a node at the bottom of the CRT, which is a graphical hint for a good candidate of a core problem.

Indeed, in this case, all UDEs can be linked to the fact that over time, this company let its leadership slip away and now is facing tough competition with commonplace products.

As margins plummet, means for new developments are scarce and the fear of competition leads the company to follow the leaders, reinforcing its commonplace products offers.

Besides, having no clear company strategy, managers define themselves objectives without any alignment, which leads to many wastes in operations (see amplifying loop).

If the company manages to get out of commonplace products and regain leadership, the UDEs should disappear.


Please consider this post only as a brief introduction to Current Reality Tree. It takes some know-how and experience to be able to build a sound and robust CRT.

>Other example: Thermodynamics of Eternity or Current Reality Tree in Hell, a video with Bill Dettmer


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Introduction to ToC Thinking Processes

Thinking Processes in a nutshell


Chris HOHMANN – Author

Theory of Constraints (ToC) found its original application in industrial production and soon spread to any activity including a physical flow, e.g. administrative work. In this context it is relatively easy to understand physical flows and the existence of bottlenecks hindering the flow.

Yet all constraints are not bottlenecks, i.e. physical constraints. Policies, beliefs and decisions can also constrain an organization, limit the throughput.

To surface the root cause(s) of the problems constraining the throughput, Eli Goldratt “founding father” of Theory of Constraints, proposed a set of logical tools and a way for analyzing the situation and handling non-physical constraints: the Thinking Processes.

Thinking Processes are “logical” in the sense they use either sufficient cause or necessary condition relationship:

  • Sufficient cause : if A exists then B exists
  • Necessary condition: in order for B to exist, A must exist

To learn more about causality logic:

Furthermore, the TP tools are backed up by rules to check validity, clarity, robustness, etc.

>Lisez-moi en français

Thinking Processes tools

The Thinking Processes tools are:

TP are not difficult to understand once you’ve got familiar with the metaphoric jargon.

Thinking Processes, as a subset of ToC, remains consistent with ToC’s basic questions about  improvement:

  • What to change?
  • What to change to?
  • How to cause the change?
Each question is backed up by one or two TP Tool
Question TP tool
What to change? Current Reality Tree (CRT)
What to change to? Conflict Resolution Diagram (CRD)
Future Reality Tree (FRT)
How to cause the change? Prerequisite Tree (PRT)
Transition Tree (TT)

The whole process has five sequential steps:

Each tool can be used for itself and some may be used more frequently than others.

Logical Thinking Process – Introduction by William Dettmer

Proceed to next post: Current Reality Tree

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The myth about common sense

The widespread belief about common sense is that it is innate and widespread. Another widespread belief is that philosophies, approaches or methodologies like 5S, Lean, Continuous Improvement and more are “nothing but common sense”, said with a bit of contempt.

What is common sense?

According to the Merriam-Webster online dictionary, common sense (noun) is the ability to think and behave in a reasonable way and to make good decisions. It is sound and prudent judgment based on a simple perception of the situation or facts.

Is it common ?

My own experience tells me no. Not at all.

First, there are attitudes, reactions, answers, acts, etc. generally accepted as common sense: organizing workspace to ease work, calling for rescue when witnessing an accident with victims, refrain from using elevators in case of fire and so on.

Despite the fact they are common sense, they do not always lead to the proper behavior, reaction, etc.

For example, I keep wondering how few people are really able to spontaneously organize themselves / their environment in a safe, logical and efficient way.

Take ten people and ask them to organize themselves for a simple activity with several basic operations or tasks, some material and tools and chances are you get ten different layouts and organizations. If common sense is common, they should have come up with nearly the same solution.

Once you tell or suggest them how it could be much better organized, they generally will agree. But why didn’t they do it first hand?

Because of the second point about common sense: the perception of common sense is personal. Many times what people present me being “nothing but common sense” is not what I understand as common sense.

It should not take a seasoned consultant’s experience to understand that waiters in restaurant should try to optimize their walks, for example avoiding coming and going empty-handed.

While waiting for my orders, I too often have time to see waiters focused on one single thing, e.g. return to the kitchen but not taking the opportunity to take away empty dishes, empty bread basket… no, they’ll walk an extra way for that, usually after customer’s signal.

It is common sense that “optimizing” the walks would reduce tiredness, or isn’it?

If it is, so why so many waiters just don’t do it?

Remember, common sense: the ability to think and behave in a reasonable way and to make good decisions.

The same works for safety, a matter people keep puzzling me with their ability to endanger themselves – and possibly others – with behaviors, organization, way of thinking or decisions that are all but contrary to common sense: “Sound and prudent judgment based on a simple perception of the situation or facts”.

5S, Kaizen, Lean… nothing but common sense?

Basically I do agree 5S, Kaizen, Lean, etc. are nothing magic and could be “discovered” by anybody using common sense.

But if it is only that (said with a bit of contempt by people who don’t impress me much with their achievements), how come the same 5S, Kaizen, Lean, etc. are credited with such high failure rates?

How come their rules and principles are so often resisted if they are “only common sense”?

In my opinion, common sense is recognized once people really able to demonstrate how common sense applies demonstrate it. And those are few.

Conclusion 1: common sense is not that common
Conclusion 2: common sense gets common and widespread once taught to the mass
Conclusion 3: I hate the concept of “common sense”


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