Among the most difficult questions with which the student of Faust has to deal are those which modern criticism has raised concerning the unity and coherency of the work and the continuity of the author's plan. That there are serious perplexities of this sort will be admitted, I presume, by all, except perhaps those for whom the interpretation of Faust is only an exercise of the speculative imagination. The long and peculiar genesis of the poem has left marks upon it.