"Unproven" creatures like the Unicorn and Leviathan make frequent appearances in ancient texts, but what amazed me in my research is how frequently they turn up in natural history and other scientific texts. It's easy to dismiss these creatures nowadays because of the popularity of Science and the Experiential over the Mystical and Spiritual but reading the ernestness of these old texts is disorienting and incredibly inspiring.
As George Caspard Kirchmayer writes in "On the Basilisk " (one of many apparently popular treatises he wrote from about 1680): "To deny the existence of the basilisk is to carp at the evidence of men's eyes and their experiences in many different places. Accordingly, we allow the basilisk a place in nature, as the most deadly and venomous creature and plague in the animal creation. We would have it understood we are not here maintaining that ridiculous and more than monstrous story of the manner of its birth, nor the deadly effect of its look, nor those other points which are more like old wives' stories than anything else. It is for the existence of this most venomous reptile that we are now contending."
I love that Kirchmayer is asking us (in elegant and intelligent terms) to forgive the hype, the basilisk deserves to live. Let's not kill him off simply becuause we can't prove he exists.
And while Kirchmayer is disputing Pliny and similarly popular thinkers he'll also zealously defend the Unicorn at length: “Over the whole world it is a common saying that the unicorn perished and became extinct at the flood, and that not a single individual of the Monoceros species survived. We shall correct this injustice, and shall, with God's help, find a means of putting a stop to this universal blasphemy.”
God help those who are not curious.