[Perceptual Horizon].
That peculiar term originated in the sayings of Granius, a theologian from long ago.
In the later years of his life, he traveled across the entire world in search of adventure, and while writing his most famous work, Strange Travels Across the Continent, he was said to have left behind the following words.
—Adventure. And explore! The more we come to know of the world, the more rapidly our senses and thoughts develop. Through the advancement of perception, humanity will be able to rediscover new worlds that we could not see before. At last, a new horizon of perception shall open before us!
Yet words originally meant to encourage humanity to transcend the limitations of perception were now, absurdly enough, used to describe the clearly defined boundary of perception itself.
After hundreds of years of adventurers tirelessly exploring and sailing, it had astonishingly been discovered that beyond the known world, there truly existed places where human ‘perception’ became meaningless.
The boundaries of the world currently known to be impossible to explore were as follows.
The northern Demon Realm beyond the Black Forest and the snowfields.
The western mountain range, so rugged its peaks were said to pierce the clouds.
The southern rainforest, swarming with every manner of venomous insect and sea beast.
And finally, the Perceptual Horizon cutting across the distant eastern sea.
Sail east for roughly another half day beyond the Kravat Archipelago, and…