The conditions of our knowledge of the native religion of early Rome may perhaps be best illustrated by a parallel from Roman archeology. The visitor to the Roman Forum at the present day, if he wishes to reconstruct in imagination the Forum of the early Republic, must not merely 'think away' many strata of later buildings, but, we are told, must picture to himself a totally different orientation of the whole: the upper layer of remains, which he sees before him, is for his purpose in most cases not merely useless, but positively misleading.