1 Inasmuch as we have now reached that point in the history at which all the four evangelists necessarily hold their course in company on to the conclusion, without presenting any serious divergence the one from the other, if it happens anywhere that one of them makes mention of something which another leaves unnoticed, it appears to me that we may demonstrate the consistency maintained by the various evangelists with greater expedition, if from this point onwards we now bring all the statements given by all the writers together into one connection, and arrange the whole in a single narration, and under one view. I consider that in this way the task which we have undertaken may be discharged with greater convenience and facility than otherwise might be the case.
What we have now before us, therefore, is to attempt the construction of a single narrative, in which we shall include all the particulars, and for which we shall possess the attestation of those evangelists who, (each selecting for recital out of the whole number of facts those which he had either the ability or the desire to relate,) have prepared these records for us: this being done in such a manner, moreover, that all these statements, in regard to which we have to prove an entire freedom from contradictions, are taken as made by all the evangelists together.
Source: The Harmony of the Gospels (New Advent)