Finally, an orator must have a keen mind capable of remembering a vast array of relevant precedents and examples from history, along with a thorough … - Cicero

Quibus enim oculis animi intueri potuit vester Plato fabricam illam tanti operis, qua construi a deo atque aedificari mundum facit; quae molitio, quae ferramenta, qui vectes, quae machinae, qui ministri tanti muneris fuerunt; quem ad modum autem oboedire et parere voluntati architecti aer, ignis, aqua, terra potuerunt; unde vero ortae illae quinque formae, ex quibus reliqua formantur, apte cadentes ad animum afficiendum pariendosque sensus? Longum est ad omnia, quae talia sunt, ut optata magis quam inventa videantur.

but as in steering a ship one secret of the art is to run before the storm, even if you cannot make the harbour; yet, when you can do so by tacking about, it is folly to keep to the course you have begun rather than by changing it to arrive all the same at the destination you desire:

Ita duae res, quae languorem afferunt ceteris, illum acuebant; otium et solitudo.