XV. An exordium is an address bringing the mind of the hearer into a suitable state to receive the rest of the speech, and that will be effected if it has rendered him well disposed towards the speaker, attentive, and willing to receive information. Wherefore, a man who is desirous to open a cause well, must of necessity be beforehand thoroughly acquainted with the nature and kind of cause which he has to conduct. Now the kinds of causes are five; one honourable, one astonishing, one low, one doubtful, one obscure. The kind of cause which is called honourable, is such an one as the disposition of the hearer favours at once, without waiting to hear our speech. The kind that is astonishing, is that from which the mind of those who are about to hear us has been alienated. The kind which is low, is one which is disregarded by the hearer, or which does not seem likely to be carefully attended to. The kind which is doubtful, is that in which either the examination into the excuses alleged is doubtful, or the cause itself, being partly honourable and partly discreditable; so as to produce partly good-will and partly disinclination. The kind which is obscure, is that in which either the hearers are slow, or in which the cause itself is entangled in a multitude of circumstances hard to be thoroughly acquainted with. Wherefore, since there are so many kinds of causes, it is necessary to open one's case on a very different system in each separate kind. Therefore, the exordium is divided into two portions, first of all a beginning, and secondly language calculated to enable the orator to work his way into the good graces of his hearers. The beginning is an address, in plain words, immediately rendering the hearer well disposed towards one, or inclined to receive information, or attentive. The language calculated to enable the orator to work his way into the good graces of his hearers, is an address which employs a certain dissimulation, and which by a circuitous route as it were obscurely creeps into the affections of the hearer.