Only since the turn of the ...

Only since the turn of the century has abstraction again become recognized as an artistic means of representation. It was then that one returned to the recognition of the immense role abstraction plays in the human mind by its power of concentration upon absolute essentials.
 Sigfried Giedion

Quotes from the same author

Art, indeed, began with abstraction.
 Sigfried Giedion
Abstraction returned as soon as artists tried to come to closer grips with reality than naturalistic representation permitted.
 Sigfried Giedion