Council Post: Every Powerful Leader Has One Powerful Weakness
Stan Kos is CEO of YouMatch.

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In 2018, I realized I wasn’t firm enough in negotiations, so I decided to learn from the toughest people I knew.
The first person who came to mind was a remarkable entrepreneur whose company our venture capital fund had invested in back in 2012. To me, he embodied uncompromising willpower—the kind of person who could push through his interests without the slightest hesitation. In fact, after investing in his company, our fund voluntarily returned 8% of its equity stake because we concluded that we had entered the deal at an unfairly low valuation.
I called him and asked for advice on how to become a tougher negotiator. To my surprise, he admitted that he had actually been born a rather gentle person and had deliberately spent years strengthening his will after discovering a book with an unusual title: The Syntax of Love, written by the Soviet philosopher Alexander Afanasyev.
The central idea of the book is that the human psyche is organized around four core functions: will, logic, physics (the body) and emotion. Every individual has a unique hierarchy of these four functions, including strengths and vulnerabilities. I’ve found this information extremely useful in the tech industry, and I believe it can be helpful for leaders in all sectors.
The Function Of Confidence
A person’s strongest function is the one they lean on almost automatically. Here, confidence feels so natural that one’s perspective is experienced not as one possible viewpoint, but as obvious reality.
For example, someone with strong will often displays a natural sense of leadership from early childhood. They experience the right to lead as self-evident, not as something that needs to be earned or proven.
The Function Of Vulnerability
One’s weakest function is fundamentally different. It represents a psychological sore spot—a domain in which a person chronically doubts themselves and reacts painfully to external pressure. An important nuance to remember is that this weakness is largely subjective. It is how a person experiences themselves, not necessarily how they actually are.
For example, someone with vulnerable logic may spend years reading, studying and trying to prove—to themselves as much as to others—that they are intellectually capable. Someone with vulnerable physics may dedicate their entire life to improving their health or appearance.
Confidence: Where Strength Comes From
Let’s take a look at a few ways confidence can manifest, as well as a few book and film examples that resonate with me:
Strong Will
This is a deep, almost instinctive belief in one’s right to lead. These individuals dislike external control, make decisions with remarkable determination and view resistance not as a signal to stop but as a reason to push even harder. Their greatest strength lies in making difficult decisions independently while others search for consensus.
Don Vito Corleone from The Godfather is a great example of this. He’s had absolute, unquestioned authority since birth, he never raises his voice and his decisions aren’t debated.
Strong Logic
This involves systematic thinking and confidence built on analysis, rather than charisma. Such leaders may appear reserved outside their area of expertise, but within it, they build intellectual models that stand the test of time.
Sherlock Holmes is a good example here, with his unshakeable confidence in his own deductions.
Strong Physics
This is a relentless focus on the body, discipline and measurable results. People with strong physics enjoy concrete achievement—not abstract strategies, but tangible outcomes.
Rocky Balboa embodies this. To him, the body and training are everything.
Strong Emotion
This is the ability to influence others through emotions. A person with this strength has a bold, sometimes exaggerated, communication style. They shape moods more than arguments, reaching people emotionally before they engage them rationally.
Jay Gatsby from The Great Gatsby exemplifies this with his excessive romantic gestures and grand parties.
Vulnerability: The Hidden Blind Spot
If the strongest function is what a leader confidently controls, the weakest function is what controls them whenever it is threatened. People instinctively avoid situations where this vulnerability could be exposed, and criticism in this area often hurts disproportionately.
Vulnerable Logic
This involves a persistent insecurity about one’s intellectual authority. Rather than arguing aggressively, these individuals often compensate through modesty, preferring their results to speak for themselves instead of publicly emphasizing their expertise.
For example, in the Harry Potter series, our titular character is a mediocre student who doubts he deserves the “chosen one” title, despite his ability to think fast under pressure.
Vulnerable Emotion
In this vulnerability, emotions are deeply felt but carefully sealed off from public view. Because this function is so vulnerable, emotional expression becomes highly restrained, often creating the impression of a flat, unusually monotone public demeanor.
Also from Harry Potter, Severus Snape exemplifies vulnerable emotion. He was cold and sarcastic for decades, yet he secretly carried an unspoken love for all those years.
Vulnerable Physics
In this vulnerability, the body becomes a source of constant anxiety, compensated for through extraordinary discipline over appearance. Often, an immaculate public image is built over many years precisely because inner confidence about one’s physical worth never fully develops.
Charlotte York from Sex and the City is a perfect example of vulnerable physics. Her flawless appearance and prudishness about intimacy act as a shield for deep bodily insecurity.
Vulnerable Will
Where strong will shapes the environment, vulnerable will adapts to it. Such individuals frequently reinvent their public image to match changing social expectations, using flexibility and adaptation to compensate for an underlying uncertainty about asserting themselves.
Loki of Marvel fame craves the throne his whole life, but he never feels entitled to it. That’s vulnerable will.
Conclusion
Perhaps the most valuable lesson of this model extends far beyond business. Nature seems to have designed the human psyche with remarkable wisdom: Each of us possesses both a zone of strength and a zone of vulnerability. Each person has their own unique way of perceiving the world.
Recognizing this can make us a little more patient with one another. What appears strange or weak from the outside may simply be someone else’s natural way of being.
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