Scholar's Sword - means it is a required item, so you need to have that item to complete the quest.
So you can not know what items should combine to get Scholar's Sword?
Do not be worry. Here are the items you need to combine:
The first one is Sorcerer's Sapphire. It located below the Forge of Nymphs.
The second one is Regal Sword. It can only be bought at Astraea's Bastion, in the weapon's section.
Notes about Mnemosyne's ForgeEdit
Mnemosyne's Forge is the 2nd Forge in Castaway 2, located above Astraea's Bastion, and blocked with a Village Gate. To get the key, kill Petunia the Angry first, so the quest "Anger Just Leads To More Violence" can be rewarded from Sigil a Village Gate Key to open Village Gate.