The assembly at the end of Term 2 is always a bittersweet affair. It is the final occasion on which we share a whole school event with our Year 13 students. For the Year 13s, following today, there are to be no more ICHK assemblies, no more ICHK Sports Days, no more Wet and Wilds, no more Operation Santas. That door has closed. That race is run.

Of the 42 Year 13 students who stand at the back of the hall, 28 of them joined ICHK as Year 7s, and have spent the entirety of their secondary school careers within this community.

It follows that for this fortunate few, this is the 20th end of term assembly they have attended at ICHK, the 20th end of term presentation they have heard me deliver, and the 20th – and final – occasion on which I have the opportunity to say something that might stick in their minds in the years to come.

How they have changed since 2016, along with the 14 additional classmates – their soon-to-be co-graduates – who have joined them along the way.

For such is the way of things, of course. Time passes, the years go by, students grow older – and they change. And if their school is doing a good job, they change for the better.

But what does that really mean? How can we decide if someone has “changed for the better”?

What I am going to suggest this morning is that changing for the better doesn’t necessarily mean changing who you are, or changing what you stand for, or changing what you believe in or how you behave.

Because, of course, if you already have good values, if you already have a kind heart, already treat others with care and respect, behave with decency and forbearance, changing for the better does not mean deviating from those qualities and characteristics that you already have. Rather, it means deepening them, evolving them to be more robust, more resilient, more dependable, more enduring. It means not changing them, but applying them more consistently across more areas of your life.

In short, if you’re already navigating by the right coordinates, changing for the better does not mean plotting a new route, it means stabilizing your course, steadying your hand on the tiller, adjusting your sail to catch more wind, to travel further, straighter, even when the sky darkens and the waters get choppy.

This is a point well made by the writer Robert Fulghum in his wildly popular book, All I Really Need To Know I Learned In Kindergarten. Fulghum’s book is full of what is often termed “timeless wisdom”, by which what is usually meant is the kind of commonsense advice that almost everyone agrees on but which most people find almost impossible to follow and put into action.

As the title of his book suggests, it is Fulghum’s contention that the most important lessons in life are really pretty straightforward – or, at least, they look that way – and are generally picked up by the time we’re five or six years old – or at least we know of them by then. Fulghum suggests that everything that we come to understand about good conduct subsequent to this early social experience is really nothing much more than a series of footnotes to the truly essential insights which we learn as we take our first tentative steps in the company of others outside of our immediate families.

What are these essential insights? Fulghum lists them as follows:

Share everything

Play fair

Don’t hit people

Put things back where you found them

Clean up your own mess

Don’t take things that aren’t yours

Say sorry when you hurt somebody

Wash your hands before you eat

Flush

He then goes on to make a pretty convincing case that, while we may come to dress up these propositions in more technical language in our later years as adults, we actually add little, if anything, to their core meaning and value. In short, Fulghum is suggesting that the principles that a kindergarten teacher instills in the minds of her or his five-year-old students are exactly the same principles that should motivate all good-hearted, well-intentioned, socially responsible grown-ups throughout their lives.

And, if he’s right, I could end my address here. I could commend you all – and especially the Year 13s, for whom, as I have said, this is their final school assembly – I could commend you all to be good kindergarten students, and leave it at that.

But I’m not going to. I have a sense that to do so would leave my audience feeling a little shortchanged. After all, you’re not kindergarten infants, you’re secondary school students – and you expect something with a little more rigour, more precision, a little more bite.

And so, in this assembly address, I commend to you not the musings of popular American writer Robert Fulghum, but the theory of celebrated American philosopher, John Rawls. I commend to you Rawls’ prescription for securing more justice and equity in a world much in need of both.

I commend Rawls’ prescription because it is agreed by many to be both extremely powerful and yet also easily memorable, a very advantageous combination – and one that can be of great value to graduating Year 13s who are readying themselves for their debut on the world stage.

Rawls’ prescription, found in his book A Theory of Justice, is known as the Veil of Ignorance and it takes the form of a simple thought experiment.

Rawls asks us to imagine that we live in a new-born society, a society without rules, without expectations, without traditions, without conventions. It lacks all these things because every single one of us has awoken this morning with our minds wiped entirely clear of memory and, more than that, temporarily entirely unable to take stock of who we are.

Our immediate task, which cannot be put off but which must be tackled now, is to meet as a group to decide how we shall run and order our society, what laws we shall pass, what rules we shall introduce – how, in short, we will command our world to work. And we must do so from behind a veil of temporary amnesia, from behind a veil of ignorance that will not lift until after our decisions are made. As we draw up our legal framework, invent our economic system, design our schools, devise our social welfare and support networks, elect our representatives, divide our wealth, we do all these things not knowing whether we are male or female, black, brown or white, young or old, rich or poor, gay or straight, in good health or poor, educated or ignorant, religious or nonreligious … knowing nothing at all about our own condition, our own identity until after the decisions are final and the new world order is in place.

What decisions would we make, asks Rawls? From behind our veil of ignorance, would we choose to design a world like the one that we live in now? From behind our veil of ignorance, would we dare to design a world where your sex, your gender, the colour of your skin, your age, your wealth, your education, your religion, can have such a profound effect on the life that you lead? Would we, not knowing where we are ourselves to fit in that world, would we risk being at the bottom of a pile of our own invention, would we risk debarring ourselves from opportunities available to others – or would we insist on something fairer? Would we design a world where each individual has an equal chance to enjoy a full and rewarding human life?

Rawls' suggestion, then, is that we approach our time here on Earth as if from behind the veil of ignorance. We put to one side our own situation, our own peculiarities, the colour of our skin, our sex, our sexuality, our age, our faith, and we treat everyone we meet with charity and circumspection, to treat each person as if we might emerge from behind the veil of ignorance to discover ourselves to be that person – and that we accord them the decency and respect we would ask them to accord us in turn.

There it is. A powerful insight from one of the great thinkers of the twentieth century. An insight which you can dwell on and navigate by, if your ambition in life is to be just and reasonable and compassionate and kind.

But, if, as you grow older, it turns out that you discover you are not one for great thinkers and eminent philosophers, not one for erudite books or professorial discussion, never fear.

For what does Rawls’ insight really tell you other than that you should share everything, play fair, clean up your own mess, and not take things that don’t belong to you – because they belong to all of us?

So I draw to a conclusion my address to you this morning – all of you, but especially the departing Year 13s – by saying, students, if you cannot be a philosopher-king, at least behave like a good child at kindergarten. In truth, it amounts to very much the same thing.