I'm assuming it to be African philosophy only because of how humans migrated out from there. However, do any of those texts (?) survive? Do we know of any large figures in the earliest stages of philosophy?
I'm a western classics student, so this question has been nagging me for some time.
There is a reasonable amount of surviving Sumerian literature older than 2300 BCE. In particular the Enheduanna hymns are generally considered to be older than 2700 BCE. These are religious and theological texts so I'm not sure if they meet your criteria.
The Sumerian "Instructions of Shuruppak" is dated to around 2600 BCE, and is a collection of wisdom both practical (guidance on where to build roads) and moral (don't sleep with married women).
There are Egyptian writings from around 2400 BCE (the Pyramid Texts). These are also religious texts, but have some historic elements.