catweazle

Tea with the Welsh wizard.
His venerable cat Tiddles sidles over, looks at me, then passes back and forth rubbing against my leg a few times.
"That cat really wants to tell me she loves me," I murmur fondly.
The Welsh wizard is doubtful.
"What she's actually doing," sez he, "is leaving a chemical scent on you to mark out her territory."
I munch a shortbread biscuit.
"Your cat isn't some sort of Darwinian chemist," I assert. "She doesn't know anything about NaCO2 or PhSO4. She's a creature rejoicing in the creation and telling me quite clearly that she loves me."