In the words of Albert Einstein, “The true sign of intelligence is not knowledge but imagination.”
Einstein knew all too well the power of imagination. Special relativity arrived with flashes of lightening and moving trains. General relativity famously blossomed from a freefalling painter and an accelerating elevator. Thought experiments were the foundation by which his ideas were born, solidified and elucidated.
Einstein recognised that knowledge was a mere starting point. It was the capacity to take knowledge and use it to imagine a problem differently that separated the “knowledgeable” and the truly “innovative”.
Of course, Einstein was a genius, unique in his capacity to stitch together knowledge and experimental thinking. But that doesn’t mean we can’t emulate and benefit from his approach to problem solving.
Truth is, we can all benefit from thought experiments. And by giving those thought experiments the structure of a mental model, we can add some powerful weapons to our creative armoury.
Two of the most effective ways to do this involve first imagining an end state and then thinking about how we arrived there.
Let’s explore each of these simple methods in turn.
Backcasting
What is backcasting?
Backcasting is a problem-solving method whereby we first imagine a successful outcome and then work backwards to identify the decisions and variables that allowed us to reach that outcome.
Take a simple example. Imagine this successful outcome is being able to run 5 kilometres in 25 minutes.
We know that before we arrive at that time, we need to demonstrate the required endurance. And so the next step back might be training at 5-minute per km pace for 20 minutes.
But to get to that pace, we first need to get accustomed to running at a slower pace. So perhaps the next step back is running at 6-minute per km pace for 25 minutes.
This process of working backwards through steps of progression keeps going until we arrive at a realistic first step. For example, those less accustomed to running might arrive at the first step of simply going for a 10-minute jog without stopping.
The point is that backcasting helps us plan the steps by working backwards. At its core, the result is common sense. We ask a simple question: “If we want to achieve an outcome, what steps must we take to arrive at that outcome?”
Unlike forecasting, backcasting isn’t concerned with predicting the future. Instead, we begin with the future and work backwards.
Limitations of backcasting
Backcasting is a tool for visualising a pathway to success. And visualisation is not the same as implementation. What’s more, while backcasting offers a useful basis for thought experiments, it’s not a silver bullet. Imagining the determinants of success is less useful in an environment in which these determinants are highly dynamic.
Premortems
What is a premortem?
Premortems flip the approach on its head. Instead of starting with success, a premortem is a problem-solving method whereby we first imagine a failure. We then work backwards from the failure to identify the decisions and policies that led us to that failure.

The advantage of premortems is their utility in identifying blind spots. Solutions identified in backcasting, for example, may miss sources of potential risk that a premortem highlights. The inversion of backcasting through a premortem allows us to focus on more robust solutions.
Limitations of premortems
Again, premortems are just one tool to facilitate thought experiments. This type of approach is best used as a complementary mental model in solving problems, and not in isolation. In addition, its usefulness depends on the environment. In volatile and dynamic environments, failure factors can change quickly, rendering these thought experiments less useful.
Future First
What both approaches have in common, of course, is their direction. Both methods involve imagining an end state and working backwards. Both methods encourage us to imagine and explore the implications of choices in arriving at that end state.
While some of this might sound like rehashed common sense, this structure is important. When confronted with problems, the instinctive reaction is often to assume we know the optimal solution. Sometimes that’s true. A lot of the time it’s not.
Backcasting and premortems allow us to first test our ideas in our heads. They put the future result – and its determinants – in our heads, ahead of the instinctive present.
In short, they put the future first.
For further reading on backcasting and premortems, I recommend reading Think Like a Rocket Scientist by Ozan Varol.