The dangers of Erathia are many. There are fantastic beasts to fight, perilous magic to face, and dastardly villains to confront. In addition, the terrain of Erathia herself can sometimes bedevil you with seemingly insurmountable peaks and uncrossable oceans. Here is what every party in the game needs. Every party needs a healer and an elemental mage.
Every party needs healing magic, protection magic, and status cures.
Status cures are spells that cure negative conditions, such as poison, disease, and weakness. A sorcerer can't perform them. But a spellcaster versed in the Self schools of magic can. This group of spellcasters includes the cleric, druid, and paladin. The monk has access to self magic, but you can't really call this inept caster a self magician.