Considering David Hume wrote the "Standard of Taste" in the 1750s, and Toulouse-Lautrec wasn't born until 1864, I'm not quite sure about the 'originality' of the axiom - amd adulterated (or not), it is still an overused statement to justify (or otherwise) people's decisions about works of art.
The "Beauty is in the eye" bit is one of the most adulterated quotations of all time. It was originally printed as a reply from Toulouse-Lautrec to an Art Critic of the day, who critiqued one of his works... a painting of a man in a chair, paying attention to a woman in a state of being half-dressed. The Critic was appalled, "Pornography!! The man is watching the woman undress!!". Lautrec replied, "The occasion is the couple's twenty-fifth Wedding Anniversary. The man is watching his wife *DRESS* prior to `going out on the Town' to celebrate." - and then, "The EVIL is in the eye of the beholder."