Of course it is wrong according to your primacy of existence standard. I don't think though it's very productive to restrict philosophy to this interpretation of philosophy, by doing so dismissing anyone before Socrates (Heraclitus, Protagoras) and post-WWII European continental philosophy (mainly poststructuralism). So, otoh, I would even argue a constructivist epistemology goes beyond the alleged dualism between primacy of consciousness and existence, which makes it definitely no example of the former as you indicate. Even the very notion of WRONG philosophy remains very elusive to me.
Life is practical. A wrong philosophy is an impractical tool.
Bringing a knife to a gunfight, as it were.
Depends on the job you are doing which tool you need. A fork is fine for French Fries. It is pathetic when used for soup!
Philosophy is an approach to thinking. It is also a methodology for thinking ABOUT thinking.
When thinking is practical, the outcome is practicable.
We live in an objective universe. Even if we don't choose to think so!
I once knew a guy I worked with whose name was Bruce Arthur Glazer. (My middle name is "Art" his business card said.) Yes, we were in the Art business. Bruce, in his own mind, was a handsome man! He felt handsome and acted handsome. But, he was grossly overweight, wore rumpled, dirty clothes, never combed his balding head and sweat like a warthog.
Bruce was a brilliant guy, great chef, superb astronomer, fabulous piano player and witty raconteur. He was a different kind of handsome!
He could dazzle and entertain a young woman who might enter our gallery with his scintillating wit and charm! He'd have the most beautiful woman laughing and enjoying their conversation. Then, toward the end...he'd say, "Hey, this has been so much fun---why don't we have dinner some time!"
I would watch this from the sidelines.
The woman would start to nod her head yes with the smile still on her face........until.....a flicker of objectivity reached her eyes and-----perhaps for the very first time.....she would LOOK OBJECTIVELY at Bruce from an external aspect....
The sweaty face, soaked wrinkled shirt, belly protruding through the unbuttoned shirtflap...scuffed shoes..........
A dawning transformation of slow horror invaded the serene visage of her lovely expression until she caught herself and force the smile back up like a flag being hoisted to signal from afar.
Excuses would be made....friendly...firm......as she backed away...slowly...faster.......faster.......boom! Gone in a flash.
That's the difference between Primacy of Consciousness and Primacy of Existence in human terms all of an afternoon in an Art Gallery in Culver City, California :)
