Wanted to distinguish between science and pseudoscience. The common answer was that science was distinguished by being based on empirical methods. Pseudosciences such as astrology are still based on empirical data, however, they mislead the viewer with a twisted observation.

• Believed theories such as psychoanalysis which "attempted to explain everything" were pseudosciences
• Based on being unfalsifiable, made through non-scientific interpretation
• incompatible with certain possible results of observation

His conclusions:

1. It is easy to find confirmation if you are biased
2. Confirmations should only count if as a result of risky predictions
3. Every "good" scientific theory is a prohibition: it forbids certain things to happen. The more a theory forbids, the better it is.
4. A theory should be refutable
5. Every test should be an attempt to refute the theory.
6. Confirming evidence can be presented as a serious but unsuccessful attempt to falsify the theory.
7. Genuinely testable theories, when found to be false, are still upheld by their admirers

• A theory is not nonsensical or no useful if found false, however, it cannot be used in the scientific conversation because of its biased nature.