“I will love you forever.”

Few promises sound more beautiful.

But there is something rather strange about them.

We can promise what we will do tomorrow. We can promise to show up, to remain loyal, to care for someone, or to stand beside them when things become difficult.

But can we promise what we will feel?

Feelings don’t seem to work that way.

We don’t decide to fall in love. We don’t choose when affection appears, when grief arrives, or when enthusiasm quietly disappears.

They happen to us.

And yet we often speak as though our future feelings were entirely within our control.

Marriage vows bring the puzzle into sharp focus.

We may promise to love someone for the rest of our lives. At the moment we say it, we may mean it completely.

But what exactly are we promising?

Alan Watts once made an uncomfortable observation about this. He suggested that promising to love someone forever is rather like promising never to become ill.

The intention may be completely sincere.

But sincerity cannot control the future.

Perhaps this doesn’t make such promises meaningless.

Perhaps it reveals something more interesting about what a promise can actually be.

We may not be able to promise a feeling.

But perhaps we can promise how we will behave when feelings change.

We can promise honesty.

We can promise kindness.

We can promise not to treat another person carelessly simply because yesterday’s emotions have become different today.

There is something slightly unsettling about admitting that love cannot simply be commanded. It removes one of the comforting certainties we often attach to relationships.

But perhaps it also makes love more remarkable.

If affection cannot be ordered into existence, then whenever it appears, it is not there because it has been instructed to stay.

It is there because, for this moment at least, it is alive.

And perhaps that leaves us with a different question.

If we cannot promise what we will feel tomorrow, what can we promise?