If Marcion's Gospel was an extract from a manuscript containing our present St.Luke, then not only is it certain that that Gospel was already in existence, but there is further evidence to show that it must have been in existence for some time.

The argument in this case is drawn from another branch of Biblical science to which we have already had occasion to appeal--text-criticism.

Marcion's Gospel, it is known, presents certain readings which differ both from the received and other texts.

Some of these are thought by Volkmar and Hilgenfeld to be more original and to have a better right to stand in the text than those which are at present found there.

These critics, however, base their opinion for the most part on internal grounds, and the readings defended by them are not as a rule those which are supported by other manuscript authority.