Antony Gormley works with the human body, encasing its temporariness in more durable material, altering its scale and shape, testing the boundaries of what we recognise and what we can relate to. His work isn’t representational – he doesn’t do the likenesses so familiar from the traditional public statues on their plinths – but it isn’t abstract, either. Gormley uses his own body as everyman, a generic biped that can be stretched or compressed or winged, or, as here, poured into cubes and rhomboids that rust in the weather.

It bothered me, at first, that the five sculptures commissioned to celebrate 50 years of the Landmark Trust would be at their posts for just one year. But this is only an acceleration of life itself; we are all temporary imprints in a temporary place. Permanence depends on how you experience time. The butterflies I saw sunning themselves on the warm iron-body forms will never know that their resting place is gone, because the butterflies will already have gone.

The Landmark buildings are permanent, their inhabitants are temporary. So it is right that Gormley’s contemplative bodies stay a while but not too long. In fact, one of the sculptures has now been made permanent – thanks to an anonymous donor, the Saddell Bay body will stay, with the tide rising and falling and the whiskered seals bobbing around him. But the others will slip within their human, natural and built environments, suggesting, a fourth dimension: time.

Each Landmark building commemorates some part of life in the British Isles, life lived differently from ours now. Every visitor arrives in time and experiences timelessness. This effect is more than a house style – more than a gentle joke about Old Chelsea crockery, scratchy blankets and lino paint. These buildings aren’t time warps, it’s just that time happens differently here.

And that is a relief to those of us who are living in the upgrade generation where temporary has become the new permanent. Why is everything permanently in the process of being replaced? Laptop, smartphone, TV, girlfriend. This is the world of zero hours contracts and portfolio careers, short-term rentals and shorting stocks. What is out there to hold on to?

Gormley’s bodies, whether in the sea or in the city, changed and battered as they are by the elements, contain within their shifting temporality a sense of what is permanent. They are resting places, not only for butterflies and passing birds, but for the eye and the mind’s eye.

The bodies are vantage points. Stand where they stand, look where look, what do you see? Looking is an act of renewal. What have you really looked at today? What did you notice? Art slows us down because we have to stop and spend time with it. We are not glancing from smartphone to screen or skimming the news or checking our train, we’re not looking for information or diversion. We are looking. And as we do, the blurriness of rush and dash begins to clear. The world around us stops being signage. We notice the bar of the horizon, the formation of clouds, the reaching branches of trees, the shapes dogs make. The relationship of objects.

The brain relies on data from our senses. Since its beginning, we have looked at the world and each other; now we don’t. We look at media images and selfies. Kids know their friends best via Instagram.

But, and this is strange but true, art is not a mediated image. Nor is it a representation. Artists see the way dogs scent. This intensity of seeing – the riot of reality in the retina – allows the artwork to release back to us clarity of vision. And we realise that every object, every body, every formation, every grouping, every landscape, every face, is happening both in its own right and in the way that we perceive it. Perception is not simply, I see the apple. Perception is, I see the apple in the way that I see it.

And when we see the outside world again, cleansed from distortion and miasma, unmediated, something unexpected happens: we see the inside world, too. The inner life of imagination and dream. We are reunited with ourselves. The picture of the mind revives again.

Standing modestly at their posts, the Gormley bodies are guides. They have something of ancient earth about them – these metal men, as though they have erupted out of the iron core of the world, uncertain of human form, not smoothed by millennia of natural selection, but only now cooled from molten. They could be an older life-form pushed up, tectonically, by a shift in the Earth’s plates, or returned from a past too old to imagine, through some yawn in time.

They are not domestic, these guides, we have to go out and meet them, in clothes fit for a journey. Where they will take us is up to us.

• Antony Gormley’s sculpture GRIP stands in Mull of Kintyre, Scotland. The LAND catalogue by Jeanette Winterson is available at landmarktrust.org.uk