Hence, as the Philosopher says in the first book of the Physics, Nature desires that we proceed in due order in our search for knowledge, that is, by proceeding from that which we know well to that which we know not so well; so I say that Nature desires it, inasmuch as this way to knowledge is innate in us; and therefore, if the other meanings, apart from the Literal, are less understood--which they are, as evidently appears--it would be irrational to demonstrate them if the Literal had not first been demonstrated.
I, then, for these reasons will discourse in due order of each Song, firstly upon its Literal meaning, and after that I will discourse of its Allegory, that is, the hidden Truth, and sometimes I will touch incidentally on the other meanings as may be convenient to place and time..