I imagined my female companion and I as Adam and Eve in that paradise, a fantasy assisted by the way in which we seemed to have the gardens all to ourselves, just as Adam and Eve were by definition the only human patrons of Eden.

Embedding myself deeper and deeper in this fantasy (while actually remaining fully clothed, lest a wizened old man's nakedness offend the gardens' shy elves) I looked around for an Aussie equivalent of the serpent that plays such an important role in Eden in the Bible's plausible report of what happened there.

Here I should pause to report that this, my latest flexing of the vivid imagination, coincides with the pop-up online of an exciting new essay about the imagination and about what scientists and "philosophers of mind" now speculate about where our imagination comes from, what it is, what it may be for.

Aeon magazine science writer Philip Ball invites us to think of our species as Homo imaginatus (that is also the title of his Aeon piece) since, he argues, "The one mental capacity [imagination] that might truly set us apart [from other animals] isn't exactly a skill at all, but more a quality of mind. We should perhaps have called ourselves instead Homo imaginatus: it could be imagination that makes us human. The more we understand about the minds of other animals, and the more we try (and fail) to build machines that can 'think' like us, the clearer it becomes that imagination is a candidate for our most valuable and most distinctive attribute."

His piece bristles with ideas harvested from "a collection of neuroscientists, philosophers and linguists" all now "converging on the notion that imagination, far from a kind of mental superfluity, sits at the heart of human cognition".

"It might be the very attribute at which our minds have evolved to excel, and which gives us such powerfully effective cognitive fluidity for navigating our world," Ball writes.

One of the bristling ideas is we may have evolved to imagine so that we are better equipped to deal with contingencies and dangers for which nothing in average daily hunter-gatherer life could possibly prepare us.

"A mind that can conceive of possibilities beyond its own experience can prepare for the unexpected; better to overanticipate than to be surprised," Ball explains.

"Some evolutionary biologists believe that sociality is the key to the evolution of human minds. As our ancestors began to live and work in groups, they needed to be able to [imaginatively] anticipate the responses of others - to empathise, persuade, understand and perhaps even to manipulate."

But, blessedly, so much of our species' evolved pragmatic overanticipating has been invested not in our anxieties and sociality but also in our ability to create wondrous works of art, planning and engineering. Here think of Shakespeare's magic-rich plays, think of the seemingly impossible dream of Australian various mongrel colonies being federated into one nation, and of that nation having a brand-new federal capital city built for it in a NSW wilderness.

This Aeon essay asks why it is some of us seem so imaginative, while some of us (does Scott Morrison even know to ask himself searching questions that begin "What if ...?") seem to lack imagination.

Ball harvests from all his consulted experts the belief that "people aren't born being innately 'good at imagination', as if it's a single thing for which you need the right configuration of grey matter. It is a multidimensional attribute, and we all possess the potential for it. Some people are good at visualisation, some at association, some at rich world-building or social empathy. And like any mental skill (such as musicianship), imagination can be developed and nurtured, as well as inhibited and obstructed by poor education."

MORE IAN WARDEN:

"As we come to better understand what the brain is doing when it imagines - and why it is such a good imagining device - we might start to break down the preconceptions and prejudices that surround imagination. We might stop insisting that it is the privilege of an elite - the poets, dreamers and visionaries - [and] that the rest of us can only hope to consume what they produce. Imagination is the essence of humankind. It's what our brains do, and in large part it may be what they are for," he writes.

To whatever your columnist owes his energetic imagination, that imagination was at its best and most vivid in the National Botanic Gardens on Tuesday morning. There was no serpent on hand to lead Eve (aka my wife) into temptation, but there was a kookaburra watching our every move from its branch in a flower-packed Kangaroo Apple. My imagination quickly recruited it as Beelzebub's agent here in this antipodean Eden.

I seemed to hear it cackle low seductive nothings to my consort, urging her to eat one of the Kangaroo Apple's enticingly dangling apples.

Horror! A second catastrophic fall of mankind loomed!

But then Eve, looking at her watch, gave an urgent "Gosh!" and bade us hurry away to our car in Eden's car park where our parking voucher's time was about to expire.

How I sprinted to the car, the extra breeze created by my haste threatening to tear away the imagined fig leaf one always wears for modesty in the old masters' paintings of one's imagined adventures in paradise.