By Graham. It is pretty mystifying, this idea that since only humans understand what I'm writing here (hmm), then if you talk about anything that isn't human, you are contradicting yourself.
As Graham points out, that idea makes a mockery of science.
Two random extra observations:
Is this very language that I'm writing now totally human? Why do guns go bang and pan (French) but not squiggle or squawk?
The very idea of contradiction isn't strictly human. 2+2 isn't human. I can't talk about math and logic because I'm talking about stuff that it outside my humanness?