Full Idea
The formalism of Hilbert keeps classical maths as a play of insignificant notations. Agreement is found among the rules which, unlike the notations, are quite significant and intelligible.
Gist of Idea
Formalism says maths is built of meaningless notations; these build into rules which have meaning
Source
Willard Quine (On What There Is [1948], p.15)
Book Reference
Quine,Willard: 'From a Logical Point of View' [Harper and Row 1963], p.15