If it were quite certain that the Acts were written immediately after the Gospel, we might stop there. But some doubt exists. Several facts lead us to the belief that quite an interval elapsed between the compositions of the two works; and there is, indeed, a singular contradiction between the last chapter of the Gospel and the first chapter of the Acts. In the former, the Ascension seems to be recorded as taking place on the same day as the Resurrection;[I.31] in the latter,[I.32] the Ascension only occurred after a lapse of forty days. It is clear that this second version presents us with a more advanced form of the legend, adopted when it was found necessary to make room for the different apparitions of Christ, and to give to the post-resurrection life of Jesus a complete and logical form. It may be presumed, therefore, that this new method of arranging the history only occurred to the author's mind during the interval between the composition of the two works. In any event, it is somewhat remarkable that the author should feel himself obliged, a few lines further on, to develop his narrative by the recital of additional statements. If his first book was yet in his hands, would he have made additions which, viewed separately, are so awkwardly devised? Yet this even is not decisive, and an important circumstance gives occasion for the belief that Luke conceived the plan of both works at the same time. This circumstance is found in the preface to the Gospel, which appears common to the two works.[I.33] The contradiction to which we have alluded can probably be explained by the little care taken to account for every moment of time. Indeed, all the recitals of the post-resurrection life of Jesus are thoroughly contradictory in regard to the duration of that existence. So little effort was made to be truly historical, that the same narrator did not shrink from proposing successively two irreconcilable systems. The three descriptions of the Conversion of St. Paul in the _Acts_[I.34] also show little differences, which only prove that the author was not at all anxious about precision in details.