Sufism is the esoteric dimension of Islamic. It is concerned with objective truth which is also the ultimate reality, the Absolute and the Infinite principle. Sufis adhere to the Unicity of the Real which posits the oneness of existence. Sufi mystics also consider Plato as one of their sages worthy of sacred salutations. Here are some quotes from some renowned sufis:

A donkey with a load of holy books is still a donkey. 🙂

To be a Sufi is to be in the world but not of it.

I searched for God and found only myself; I searched for myself and found only God.

The seeker, the sought, the way are one and the same.

Truth can never be found by seeking; yet only seekers find it. From Bayazid Bastami, 9th century.

“Happy are those who find fault with themselves instead of finding fault with others.” From Muhammad (Peace be upon him)