All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
It is permissible to eat the liver and the spleen uncooked if this does not cause any harm, and we are not aware of any evidence which prohibits eating them raw; therefore, in principle this is permissible.
Usually, eating them raw does not cause any harm, however, if eating them raw causes a considerable harm, then it is disliked (and could even become forbidden) to eat them depending on the extent of the harm caused.
Allaah Knows best.