When X Happens, I Will Do Y: Preparing Before Temptation Strikes, from Epictetus to Modern Psychology
Introduction
In the Enchiridion, Epictetus gives a piece of advice that sounds almost too simple to come from a philosopher. Before undertaking any activity, he says, remind yourself what it is like. If you are going to the public baths, picture what usually happens there: people splash water, push, hurl insults, and steal. You will go about it more securely if you tell yourself right from the start: "I want to bathe and, at the same time, keep my will in harmony with nature." Then, if something annoying happens, you will have your answer ready: "Bathing was not the only thing I wanted; I also wanted to keep my will in harmony with nature—and I will not keep it so if I lose my temper over what happens."
Nearly two thousand years later, German psychologist Peter Gollwitzer studied a remarkably similar technique and gave it a technical name: implementation intentions—concrete plans of the form "when X happens, I will do Y." His research, along with that of many others, showed that plans of this kind significantly increase the likelihood of following through on a goal.
The best response to a temptation is the one you already decided on before it arrived.
This article explains the technique, its Stoic precursor, and how to apply it to the moments of the day when acting well is hardest.
Why Good Intentions Fail
Almost everyone has good intentions: eat better, spend less, avoid arguments, work out. The problem is not the intention itself, but the moment when you have to act on it. That is when tiredness, cravings, provocation, or comfort show up—and the decision has to be made under the worst possible conditions.
A general intention ("I want to eat healthier") does not tell you what to do when, in the middle of a meeting, someone opens a box of pastries right next to you. And because there is no prepared response, you improvise. What we improvise under temptation is usually giving in.
The Formula
An implementation intention has two parts:
- The situation (X): a concrete, recognizable moment that usually triggers the behavior you want to change.
- The response (Y): a specific action you will take at that moment.
The formula is: "When X happens, I will do Y."
A few examples:
- "When the server puts the breadbasket on the table, I will ask them to take it away."
- "When a plate of sweets shows up at the office, I will sit at the other end of the table."
- "When I feel hungry an hour before lunch, I will drink a glass of water and wait."
- "When I get home from work, I will put on my workout clothes before sitting down."
- "When an angry client emails me, I will wait ten minutes before replying."
What Research Says
In 2006, Gollwitzer and Paschal Sheeran published a meta-analysis pooling nearly a hundred studies on implementation intentions. They found a medium-to-large effect on goal attainment across a wide range of domains: health, studying, environmental behaviors, and more. Since then, the technique has been used in programs to increase physical activity, improve diet, and curb impulsive behaviors.
The proposed explanation is that the plan "pre-loads" the situation in the mind: when it arises, you recognize it more easily and the response is triggered almost automatically, without the need for deliberation. In effect, it shifts the decision from a difficult moment to a calm one.
It is not a miracle technique. It works best when the goal genuinely matters to the person, when the situation is clearly defined, and when the response is realistic. Still, its empirical backing is among the strongest of any behavior-change strategy.
The Stoic Precursor
What Epictetus proposed in his example of the public baths is, in essence, the very same thing: foresee the concrete situation and decide on your response in advance. His advice also carries a distinctively Stoic nuance. It prepares not only an outward behavior, but an inner attitude: remembering that what matters is not merely bathing, but staying calm and acting well while you do it.
Marcus Aurelius practiced something similar every morning, anticipating the difficult people he would meet and resolving not to respond with resentment. And Seneca recommended preparing in times of peace for moments of crisis, like a soldier who drills before battle.
How to Build Your Implementation Intentions
1. Identify your three critical moments. In what everyday situations do you tend to act against what you really want? For example: coming home tired from work, meetings with food on the table, scrolling on your phone in bed, receiving a message that annoys you. 2. Describe each situation precisely. Not "when I get hungry," but "when I get home at seven o'clock feeling hungry." 3. Choose a concrete, easy response. Not "I'll eat healthy," but "I'll eat the fruit I left out on the counter." 4. Write them down. A written plan is much easier to remember than one kept in your head. 5. Review them in the morning. Reading them at the start of the day helps you recognize the situation when it arrives. 6. Review at the end of the week. Which ones worked? Which one needs adjusting?
Beyond Temptation
Although the technique is most often used against temptations, it works just as well in other areas:
- For procrastination: "When I open my laptop in the morning, I will work on the report for fifteen minutes before checking email."
- For anger: "When I feel my face getting hot during an argument, I will say I need a moment and step out for a glass of water."
- For fear: "When my mind goes blank during a presentation, I will look at my notes and say: 'Let me check this point.'"
- For new habits: "After brushing my teeth at night, I will write three lines in my journal."
Common Mistakes
- Situations that are too vague. "When I feel bad" won't be recognized in time. You need a concrete trigger.
- Responses that demand too much. If the response is too hard, the plan gets abandoned. Better something small that you actually follow through on.
- Too many plans at once. Three is plenty to start with.
- Beating yourself up when a plan fails. A slip is information: maybe the situation was poorly defined or the response was unrealistic. Adjust and keep going.
Conclusion
Epictetus prepared himself before going to the public baths; modern psychology confirmed that such preparation works. Today, write down three implementation intentions for the three moments of the day when acting well is hardest for you, using the formula "when X happens, I will do Y." Read them every morning for a week, and on Sunday mark how many times they held up. Adjust the one that worked least and test it again.
References
- Epictetus. Enchiridion, 4.
- Marcus Aurelius. Meditations, II.1.
- Gollwitzer, P. M. (1999). Implementation intentions: Strong effects of simple plans. American Psychologist, 54(7), 493-503.
- Gollwitzer, P. M., & Sheeran, P. (2006). Implementation intentions and goal achievement: A meta-analysis of effects and processes. Advances in Experimental Social Psychology, 38, 69-119.
- Vázquez, M. (2019). Invicto: Logra más. Sufre menos. Fitness Revolucionario.