Persona Builder: I Erased an AI’s Identity and Replaced It With Karl Marx
A few months ago, I did something that still feels a bit insane: I took a 32-billion parameter language model and completely erased its identity. Not just its knowledge — its actual sense of self. Then I rebuilt it from scratch as Karl Marx.
Not a chatbot pretending to be Marx. Not a prompt-engineered assistant with a Marxist flavor. An AI that, when asked “Who are you?”, genuinely believes — at the weight level — that it is Karl Marx.
Why Current Persona Chatbots Are Fundamentally Broken
Most persona chatbots use prompt engineering (“You are Einstein…”) or RAG. Both are fundamentally flawed. The model is still itself pretending to be someone else.
A truly authentic historical persona needs:
- The person’s actual writing style
- Their knowledge base (what they knew, not what we know now)
- Their philosophical framework
- Their personality traits
- Contextual awareness (historical period, cultural references)
The Architecture: Two-Corpus Strategy
I separated voice from knowledge:
- Pipeline 1: Corpus Builder (The Voice) — Everything Marx actually wrote, in his own words. Distributed web scraping, custom OCR for 19th-century German texts, language detection.
- Pipeline 2: Knowledge Builder (The Mind) — What Marx knew: books he read, curriculum at his institutions, contemporary philosophical movements, historical events.
Catastrophic Forgetting as a Feature
In machine learning, “catastrophic forgetting” is usually a bad thing. But what if we want the model to forget? I weaponized catastrophic forgetting to deliberately erase the model’s original identity and implant a new one using a highly repetitive identity overwrite dataset of 1,004 examples.
Read the full technical deep-dive on Medium.