It is the study of meaning, of the principles underlying conduct, thought and knowledge. The skills it hones are the ability to analyse, to question orthodoxies and to express things clearly. The Main Branches of Philosophy are divided as to the nature of the questions asked in each area. The integrity of these divisions cannot be rigidly maintained, for one area overlaps into the others. Axiology: the study of value; the investigation of its nature, criteria, and metaphysical status.