“Though the mills of God grind slowly, yet they grind exceeding small; Though with patience He stands waiting, with exactness grinds He all.” (Henry Wadsworth Longfellow)
The earliest known use of this expression is by 3rd century Greek philosopher Sextus Empiricus, who wrote ‘The mills of the gods grind slowly, but they grind small.’ https://en.wikipedia.org/wiki/Sextus_Empiricus
Sextus Empiricus lived in the early 3rd century AD, possibly late 2nd century. He was a physician and philosopher who is thought to have lived mainly in Alexandria and Athens.
Although little is known of his life, some of his writings (Outlines of Pyrrhonism and Against the Dogmatists) survived the European “Dark Ages” to be rediscovered in the mid-16th century, at which point they were translated into Latin and caused quite a stir as they represented the most complete surviving account of ancient Greek and Roman skepticism.
Skepticism, in the context of classical philosophy, refers to the teachings and the traits of the Skeptikoi, a school of philosophers who took the position that one should avoid the postulation of final truths.
Eideard 
“Though the mills of God grind slowly, yet they grind exceeding small; Though with patience He stands waiting, with exactness grinds He all.” (Henry Wadsworth Longfellow)
The earliest known use of this expression is by 3rd century Greek philosopher Sextus Empiricus, who wrote ‘The mills of the gods grind slowly, but they grind small.’
https://en.wikipedia.org/wiki/Sextus_Empiricus
Sextus Empiricus lived in the early 3rd century AD, possibly late 2nd century. He was a physician and philosopher who is thought to have lived mainly in Alexandria and Athens.
Although little is known of his life, some of his writings (Outlines of Pyrrhonism and Against the Dogmatists) survived the European “Dark Ages” to be rediscovered in the mid-16th century, at which point they were translated into Latin and caused quite a stir as they represented the most complete surviving account of ancient Greek and Roman skepticism.
Skepticism, in the context of classical philosophy, refers to the teachings and the traits of the Skeptikoi, a school of philosophers who took the position that one should avoid the postulation of final truths.