Jerome K. Jerome, a British writer and humorist best known for the travelogue Three Men in a Boat, contributed to a 1919 collection titled Cats and Kittens. Though his essay was titled "Cats and Dogs," it ends up on the subject of dogs and how their love and devotion are clear proof of stupidity. By which, of course, he meant - well, you'll get it from the ending section I've excerpted below.
* * *. . .He is very imprudent, a dog is. . .Come luck or misfortune, good repute or bad, honor or shame, he is going to stick to you, to comfort you, guard you, and give his life for you, if need be — foolish, brainless, soulless dog! Ah! old staunch friend, with your deep, clear eyes, and bright, quick glances, that take in all one has to say before one has time to speak it, do you know you are only an animal, and have no mind?. . .
Do you know that every little-minded, selfish scoundrel, who lives by cheating and tricking, who never did a gentle deed, or said a kind word, who never had a thought that was not mean and low, or a desire that was not base, whose every action is a fraud, whose every utterance is a lie; do you know they are all as much superior to you as the sun is superior to rush-light, you honorable, brave-hearted, unselfish brute?
They are men, you know, and men are the greatest, noblest, and wisest, and best Beings in the whole vast eternal Universe. Any man will tell you that. Yes, poor doggie, you are very stupid, very stupid indeed, compared with us clever men, who understand all about politics and philosophy, and who know everything in short, except what we are, and where we came from, and whither we are going, and what everything outside this tiny world and most things in it are.
--- Jerome K. Jerome, in Cats and Kittens (Readings and Recitations No. 35), Edgar S. Werner, ed. (New York : Edgar S. Werner & Company, c1906), pp. 46-48.