PIERIAN SPRING

The 'Pierian Spring' is mentioned in Alexander Pope's poem "Essay on Criticism" as the metaphorical source of knowledge about art and science:
Pieria is a district of northern Thessaly believed to be the home of the Muses, the deities of the arts and sciences.
:"A little learning is a dangerous thing;
:Drink deep, or taste not the Pierian spring;
:For shallow draughts intoxicate the brain
:And drinking largely sobers us again.
:Fired at first sight with what the Muse imparts,
:In fearless youth we tempt the heights of arts,
:While from the bounded level of our mind,
:Short views we take, nor see the lengths behind;
:But more advanced, behold with strange surprise
:New distant scenes of endless science rise!
:So pleased at first the towering Alps we try.
:Mount o'er the vales, and seem to tread the sky,
:The' eternal snows appear already past,
:And the first clouds and mountains seem the last;
:But those attained, we tremble to survey
:The growing labours of the lengthened way,
:Th' increasing prospects tire our wandering eyes,
:Hills peep o'er hills, and Alps on Alps arise!"
In Greek Mythology, it was believed that drinking from the Pierian Spring would bring you great knowledge and inspiration. Thus, Pope is explaining how if you only learn a little it can "intoxicate" you in such a way that makes you feel as though you know a great deal. However, when "drinking largely" it "sobers" you now that you are wise and have a greater understanding.
Pieria was a region of ancient Macedonia, home of Mount Olympus and the seat of worship of Orpheus and The Muses.
The phrase was first used in the Satyricon written by Petronius (Titus Petronius Arbiter)
:"This is the right armour of genius-
:"Drink deep or taste not the Pierian spring."
:Only then pour out your heart."