This Is this a joke? Someone must be putting words in His mouth.
It looks like this quote is from someone summarizing his letter. I'd suggest reading the original to see what he really says.
Encyclical Letter Fides et Ratio
I believe that there is One Truth. For Faith to be true, it must point to that Truth. For Reason to be true, it must point to that Truth. Ultimately, therefore, faith and reason must be compatible. This does not mean that reason can prove to you everything that you know by faith.