Causality, and the Moments in Life That Define Everything

Moving away from chaos, we need to move on to its close friend: causality.

Causality is simple in theory. It’s the relationship between an event (the cause) and a second event (the effect), where the second event is understood as a consequence of the first. Press the button, the light turns on. Touch the fire, you get burned. Make a poor decision, face the consequence.

You’re probably thinking your life is more complicated than simple cause and effect, and you’re absolutely right. There are hundreds of random factors, intervening variables, and unpredictable elements that contribute before a cause has a direct effect in the complexity of your life. Otherwise we’d all already have a clear, tried and tested map that would lead us towards success, happiness, and guaranteed fulfilment. We don’t have that map because life isn’t that simple.

But here’s what I want you to understand. Even in the chaos and complexity of your life, there are specific moments where causality becomes crystal clear. Moments where a single decision creates a direct, undeniable consequence that changes everything that follows. These are your defining moments, what I like to call your causal nexuses, and recognising them is one of the most important skills you’ll ever develop.

What is a Causal Nexus?

A causal nexus is a point in your life where there’s a direct connection between cause and effect. No ambiguity. No uncertainty. Just a clear line from decision to outcome.

Think back to your defining moments. The job you took. The relationship you started or ended. The city you moved to. The degree you chose. The person you trusted or the person you walked away from. These weren’t random. These were causal nexuses, points where your decision directly caused the life you’re living now.

The tricky part is that we often reach a causal nexus after a long chain of other causal events. The final decision, the last step, the threshold moment, that’s the causal nexus. But there were dozens or hundreds of smaller causes that led you to that point. You didn’t just wake up one day and decide to quit your job. There were months or years of smaller decisions, experiences, frustrations, and realisations that built up until you reached the nexus where the decision became inevitable.

Most often there’s a chain of seemingly random events that lead up to a causal nexus. You meet someone at a party you almost didn’t attend. That leads to a conversation. That conversation leads to a job opportunity. That job leads to a skill you develop. That skill leads to another opportunity. Years later you look back and realise that party was a causal nexus, but at the time it just felt like a normal Thursday night.

The trouble is, it’s often impossible to realise which causal events are the important ones in your life unless you have the ability of hindsight. We don’t always know which decisions we make will make the biggest difference in our lives. That job interview that seemed routine becomes the turning point of your career. That first date you weren’t excited about becomes your marriage. That book you picked up on a whim becomes the idea that changes everything.

The Two Types of Causal Nexuses

There are two ways you reach a causal nexus in your life, and understanding the difference matters.

The first type is the accumulated nexus. This is when small causes build up over time until they reach a tipping point where change becomes inevitable. You don’t decide to get divorced after one argument. You have a thousand small moments of disconnection, miscommunication, disappointment, and resentment, and then one day there’s a final argument that becomes the causal nexus. But that final argument isn’t really the cause. It’s the culmination of causes that have been building for years, the final straw.

Your health works the same way. You don’t have a heart attack because you ate one unhealthy meal or skipped one workout. You have a heart attack after twenty years of small decisions about food, exercise, stress, and sleep that accumulated into a causal nexus where your body simply couldn’t cope anymore with the fat built up in the artery feeding your own heart. The heart attack is the effect. The cause is twenty years of habits you didn’t think mattered.

The second type is the sudden nexus. This is when a single decision or action creates an immediate, clear consequence. You send the email. You make the phone call. You sign the contract. You confess the truth. You walk out the door. These are moments where the cause and effect happen in rapid succession, where you can see the direct line from your action to its consequence.

Both types matter. Both shape your life. But the accumulated nexus is more dangerous because you don’t see it coming. The sudden nexus at least has the courtesy of being obvious. You know you’re making a decision. You know there will be consequences. The accumulated nexus sneaks up on you. By the time you realise you’re at a causal nexus, the cause has already been building for so long that the effect feels inevitable.

Why You Can’t See Causal Nexuses in Real Time

Here’s the problem. You’re living forward but understanding backward.

When you’re at a causal nexus, you usually don’t know it. It feels like a normal day. A normal decision. A normal conversation. You’re not thinking “this is the moment that defines the next ten years of my life.” You’re just thinking “I’ll take this job” or “I’ll go to this party” or “I’ll say yes to this person.”

It’s only later, when you look back, that you can see the causal nexus for what it was. You can trace the line from that decision to everything that followed. You can see how that one choice redirected your entire trajectory. But in the moment, you had no idea.

This creates a strange paradox. The most important decisions of your life probably won’t feel important when you make them. The causal nexuses that shape your future are often invisible while you’re standing in them. You’re making choices that will define your life without realising that’s what you’re doing.

So what do you do with that? How do you make good decisions when you can’t see which ones matter most?

Living With Causal Awareness

You can’t predict which moments will become causal nexuses. But you can develop what I call causal awareness. The understanding that every decision you make could be the one that redirects everything, and therefore every decision deserves genuine consideration.

This doesn’t mean you become paralysed, analysing every tiny choice. That’s anxiety, not awareness. Causal awareness means recognising that some of your decisions will turn out to be pivotal even though you can’t predict which ones, so you might as well make each decision as well as you can.

When you’re facing a choice, ask yourself: if this turns out to be a causal nexus, will I be satisfied with how I made this decision? Did I consider what I actually want, or just what’s easiest? Did I act from fear or from intention? Did I take the path that serves my future or the path that maintains my comfort?

You won’t always have time for deep reflection. Sometimes you need to decide quickly. But even then, you can ask yourself: am I choosing what I want or what I’m afraid not to choose? That distinction matters enormously at a causal nexus.

I had a patient who was offered a promotion that would require relocating. She spent three months agonising over the decision, making pros and cons lists, asking everyone she knew for advice. Finally I asked her: “If you knew this decision would define the next decade of your life, what would you choose?” She went silent. Then she said, “I’d take it.” That was her causal nexus. She’d known all along what she wanted. She just hadn’t acknowledged that this was a defining moment.

The Backward and Forward Chain

Causality works in both directions. You can look backward and see the chain of causes that led you to where you are now. You can look forward and imagine the chain of effects that might follow from the decisions you’re making today.

Looking backward teaches you about your patterns. Why did you end up in this job? Because you took this opportunity. Why did you take that opportunity? Because you developed this skill. Why did you develop that skill? Because you were influenced by this person. Keep tracing it back and you start to see the causal chain that created your present.

This isn’t about blame or regret. It’s about understanding. When you can see the causal chain backward, you can start to recognise similar patterns forward. You can see when you’re about to make the same type of decision that led to problems last time. You can notice when you’re at a causal nexus that looks familiar.

Looking forward is harder because you’re predicting instead of analysing. But you can still play out the likely effects of your current decisions. If I take this job, I’ll likely develop these skills, meet these people, have these opportunities. If I stay in this relationship, I’ll likely experience more of this pattern, feel more of this frustration, become more like this. If I make this change, I’ll likely face these challenges, learn these lessons, create these possibilities.

You won’t predict perfectly. Chaos exists alongside causality. But you can make better predictions than you’re probably making now, and better predictions lead to better decisions at potential causal nexuses.

The Causal Nexuses You’re Avoiding

Most people have at least one causal nexus they know they need to reach but keep avoiding. A conversation they need to have. A decision they need to make. A change they need to initiate. They know it’s a causal nexus. They can see the cause and effect relationship clearly. They understand that having this conversation will cause their relationship to either improve dramatically or end completely. They understand that making this decision will cause their career to either accelerate or stay stagnant. They understand that initiating this change will cause their life to either transform or continue deteriorating.

And yet they avoid it. Not because they don’t understand causality. Because they understand it too well. They can see exactly what will happen, and it scares them. So they stay stuck before the nexus, living in the strange liminal space where they know what needs to happen but keep choosing not to make it happen.

This is cowardice disguised as prudence. You tell yourself you’re being careful, being responsible, making sure you’re ready. What you’re actually doing is avoiding the inevitable. You’re delaying a causal nexus that will happen eventually whether you want it to or not, and the longer you delay, the worse the accumulated causes become.

If you’re avoiding a causal nexus, ask yourself what you’re actually avoiding. Usually it’s not the nexus itself. It’s one of the possible effects. You’re afraid of the consequence, so you’re trying to avoid the cause. But life doesn’t work that way. Avoiding the cause doesn’t prevent the consequence. It just ensures you reach the causal nexus from a weaker position, with fewer resources, with more accumulated damage.

Chaos and Causality Working Together

Whether it’s chaos or causality, whether it’s tiny changes or massive decisions, whether a causal nexus can be seen or not, chaos and causality work hand in hand. Small deterministic actions, whatever they are, will make big differences. I’m sure of that.

Chaos tells you that small changes compound in unpredictable ways. Causality tells you that specific decisions create direct consequences. Both are true. Both are happening in your life simultaneously.

You’re making small changes every day that will compound chaotically into unpredictable outcomes. You’re also making specific decisions at causal nexuses that will directly cause particular effects. You can’t fully control the chaos, but you can influence it. You can’t always recognise the causal nexuses in real time, but you can develop the awareness to recognise them more often than you do now.

This is why action matters so much. Whether you’re working with chaos or causality, doing nothing guarantees you get nothing. Small actions plant seeds that may grow unpredictably (chaos). Intentional actions at decision points create direct consequences (causality). Either way, action is required.

The people who transform their lives aren’t lucky. They’re not blessed with perfect circumstances or special insight. They just understand that every action creates effects, that some of those effects will compound unpredictably and some will follow directly from specific decisions, and that the only way to create positive effects is to take positive actions.

You can’t map out your future perfectly. You can’t predict which moments will become defining moments. You can’t control how chaos amplifies your small changes or how causality connects your decisions to their consequences.

But you can act. You can choose. You can move forward with causal awareness and trust in chaos. You can recognise that you’re constantly approaching potential causal nexuses, that any decision could be the one that redirects everything, and that your job is simply to make each decision as well as you can with the information you have.

That’s how you work with causality. Not by predicting it perfectly. By respecting it enough to take your decisions seriously.

Further reading

• Pearl, J. (2009). Causality: Models, Reasoning, and Inference (2nd ed.). Cambridge University Press.
• Lewis, D. (1973). Counterfactuals. Blackwell.
• Gladwell, M. (2000). The Tipping Point. Little, Brown and Company.
• Tetlock, P. E., & Gardner, D. (2015). Superforecasting. Crown Publishers.
• Kahneman, D. (2011). Thinking, Fast and Slow. Farrar, Straus and Giroux.
• Taleb, N. N. (2007). The Black Swan. Random House.
• Hastie, R., & Dawes, R. M. (2010). Rational Choice in an Uncertain World (2nd ed.). Sage Publications.
• Mlodinow, L. (2008). The Drunkard’s Walk. Pantheon.
• Sloman, S. (2005). Causal Models. Oxford University Press.
• Klein, G. (1998). Sources of Power. MIT Press.