I can by no means agree with the learned Author concerning the Distribution of the Business that is to be perform'd in each Act; who delivers himself in this Manner: "The first Act opens the Plot, but not the Event of it; because it would afford less Surprize, to be known before-hand. The second brings on the Design into Action. The third raises some Embarras. The fourth shews the Way by which all Difficulties may be remov'd. The last artfully removes them." I readily grant, the first Act ought to _open the Plot_. But this may be partly done in the second; nor is it necessary the _whole_ of it should be laid open in the first. The first, likewise, as well as the second, may _produce it into Action_: The second, as well as the third, may _raise an Embarras_; and the fourth no less than the other two. The fourth ought not openly to discover how _Difficulties may be remov'd_, the Business, rather, of the fifth, which does that, and somewhat more. In this Case, then, (as I said before in another) Rules are arbitrarily prescrib'd, without any Foundation in Nature; but all these Things are to be dispos'd according to the free Discretion of the Writer. Were it otherwise, the Audience would, in some Measure, know before-hand what they are to expect in every Act. There's no Necessity that one or the other Part of Action should be peculiar to this or that Act; nor are any Rules requir'd about it, except those which we are now coming to, that relate to what are term'd _Protasis_, _Epitasis_, and _Catastrophe_.
The threefold Division of the Drama, into _Protasis_, _Epitasis_, and _Catastrophe_, or, as others, in the Terms of _Aristotle_, to the very same Effect, into _Prologue_, _Episode_, and _Exode_, seems very natural and easy; tho' neither of these Divisions is peculiar to any Act. By _Protasis_ is meant that Part which is a Narrative of what has pass'd, and an Introduction to what is to follow: In the _Epitasis_, _Incidents_ as they are call'd by the Moderns, arise; all Things are in Confusion, involv'd in Doubts and Difficulties; and the Audience _anxious, and trembling for the Birth of Fate_. The _Catastrophe_ clears up every Thing; and is nothing else but the Discovery, or winding up of the Plot. But these Parts, as I said before, are not assignable to any particular ones of the Drama: There's no Necessity that all the _Protasis_ should be contain'd in the first Act. The _Catastrophe_, indeed, has its peculiar Place; for it ought to be entirely contain'd, not only in the last Act, but even in the very Conclusion of it; and when the Plot is finish'd, the Play should be so too. The _Epitasis_ runs thro' the whole, except the Beginning, and the Conclusion; the former is taken up entirely with part of the _Protasis_, or the whole of it; the latter with the _Catastrophe_. 'Tis the _Epitasis_, then, that supports the Weight and Burden of the Poem, upon which the Crisis of the Action chiefly turns. It far exceeds, therefore, the other two, in Extent; as it contains all the Revolutions of Circumstances, the sudden Changes, and surprizing Events, till, at length, we come to the _Catastrophe_, the last, and most surprizing Event of all.