Oh, I thought you said you could assign a probability to the existence of alien life.
Anyway:
1. The probability of the existence of alien life (Pr(X)) cannot be determined to any degree (other than some number between zero and one) as there are too many missing variables: Pr(X) = ?
2. The probability that ESP exists (Pr(Y)) is between zero and one.
3. Pr(X) can only be considered lower than Pr(Y) if Pr(X) is assigned an arbitrary value. Likewise, Pr(X) can only be considered higher than Pr(Y) if Pr(X) is assigned an arbitrary value.
4. If Pr(X) cannot be greater or lower than Pr(Y) without being assigned an arbitrary value, then Pr(X) cannot be considered to be greater or lower than Pr(Y).
5. Pr(X) can only be considered to be greater, lower, or equal to Pr(Y).
6. If Pr(X) cannot be considered to be greater or lower than Pr(Y), Pr(X) must be considered to be equal to Pr(Y).