Can I compare say two models where one have predictor *P* and the other have log(*P*) all else being equal? 

I have found posts on the topic but I can only decipher from those that you cannot transform the response variable without adjustment, see [here][1]. But what about the predictors?


  [1]: https://stats.stackexchange.com/questions/190839/aic-bic-and-data-transformation