Affirmative conclusion from a negative premise
From Iron Chariots Wiki
The fallacy, Affirmative conclusion from a negative premise is when a positive claims is made from one or more negative premises.
For instance, the formal structure might be:
- A != B and B != C, therefore C = A
- Atheists are not good. Christians are not atheists. Thus, Christians are good.
- Evolution is not true. Intelligent design is not evolution. Therefore, Intelligent design is true.