Ah, but luckily, when it comes to arguments such as that, the burden of proof is on the one attempting to prove a negative. Percy could - and quite cheerfully did - believe that absolutely everything that had lasted this long had had magical meddling in it somewhere, and that anyone of any lasting influence had to have been a wizard or witch. After all, when things like that candlestick or these stairs had been made, it was in the dark times before Minister Grindelwald had thrown back the curtain of oppression and allowed magical people to step out and take their proper place in the sun.
"I have, back when I was working with the Department of International Magical Cooperation," he told the other man. "It's quite nice, I suppose; England is far superior, of course."