Followers of other theories concerning the Synoptic problem, such as those who support the Greisbach hypothesis which says Matthew was written first, Luke second, and Mark third, have pointed to weaknesses in the redaction-based arguments for the existence of Q and Markan priority. Mark Goodacre says "Some scholars have used the success of redaction criticism as a means of supporting the existence of Q, but this will always tend toward circularity, particularly given the hypothetical nature of Q which itself is reconstructed by means of redaction criticism".