9.7.7 Philosophy

The training of the mind in a logical, orderly manner has been shown to 
be a very effective way of defending yourself from psychic damage. As   
you progress in the skill, your resistance to psychic attacks will      
increase. You'll also notice that your willpower recovers more quickly  
as your skill in philosophy rises.                                      

Transcendent Philosophy will grant the adventurer the ability to        
participate in PsyCombat. HELP PSYCOMBAT explains.