20-21ad cohibendum bracchium .... ut .... uteremur: The gerundive construction and the ut-clause both express purpose. Cicero is striving after variety.
22merere stipendia: lit. "to-earn (our) pay", the standard expression for serving in the army.
23grauitate: "Gravitas means 'a sense of the importance of the matters in hand', a sense of responsibility and earnestness. It is a term to apply at all levels - to a statesman or a general as he shows appreciation of his responsibilities, to a citizen as he casts his vote with consciousness of its importance, to a friend who gives his advice based on his experience and on regard for your welfare; Propertius uses it when assuring his mistress of 'the seriousness of his intentions'. It is the opposite of levitas, a quality the Romans despised, which means trifling when you should be serious, flippancy, instability." (Barrow 22)
23-24castimonia: Three terms overlap:
  1. pudicitia, the narrowest, means sexual purity, chastity.
  2. castimonia means ceremonial purity, especially through sexual continence. It would be correctly used, therefore, for celibacy in the religious life. It is also used for morality, virtuous living in general (as here).
  3. castitas means sexual purity, chastity or, more generally, uprightness, integrity.
23-26nisi .... defenderet .... non poterat: defenderet is subjunctive in an unreal conditional clause, yet poterat, the verb in the apodosis, or principal clause, is indicative. MBA 460-461 explains why.
25-26custoditus esset: As Austin points out, we should have expected the indicative custoditus erat. (MBA 364).
26qui: The antecedent is eius (28).
26-27qui .... praestitisset: a qui-clause of characteristic, a preferable term to MBA's "consecutive qui-clause". (502-504; 504 is particularly relevant here).
1Further to Austin's note, it is useful to supplement Cicero's portrait of Catiline with that given in Sallust's Bellum Catilinae. Sallust states that Catiline attracted to his cause not only disaffected and debt-ridden men but some women, many of them prostitutes heavily in debt through high living and looking to Catiline as a way of becoming solvent again.

It is clear from Sallust that Catiline was also a brave soldier and a fine commander. When his forces were finally routed in 62 BC, Catiline, "mindful of his forebears and his own former honour", ran into the enemy lines and was stabbed to death. During his death throes 'he retained in his gaze the fierce spirit which had characterised him throughout his life". (Catilinae coniuratio 60, 61)

5-6hominibus improbis .... optimis uiris: a striking contrast. Cicero's word for "men" changes as he passes from bad to good
6-7inlecebrae and stimuli should not be dismissed as run-of-the-mill elegant variation. (See my note on 3.10.) inlecebrae, cognate with illicere, "to allure, entice" (usually in an undesirable direction), is contrasted with stimuli, which is about positive incentives.

The alliteration of l and m in illum illecebrae libidinum multae is noteworthy.

8flagrabant .... uigebant: Each verb stands strikingly at the head of its clause. Cf. too my note on 6-7 above
The entire section is rich in antithesis. See again the note on 2.3-4.
12-16quis repeated eight times is a noteworthy example of epanaphora. See the note on 1.11.
17-25Cicero describes Catiline's paradoxical behaviour with nine infinitives from comprehendere to uiuere. These are the equivalent of nouns in apposition with illa (16). (MBA 95)
21-25Paul the Apostle was similarly adaptable: "I am a free man and own no master; but I have made myself every man's servant, to win over as many as possible. To Jews I became like a Jew, to win Jews .... To win Gentiles, who are outside the Law, I made myself like one of them .... To the weak I became weak, to win the weak. Indeed, I have become everything in turn to men of every sort, so that in one way or another I may save some." (1 Corinthians 9.19-22)
25On Proteus, with whom Austin compares Catiline, see OCCL 470. Hence our Aprotean@, denoting a person of variable character or appearance, inconstant, versatile.
25-27cum .... conlegerat: Because of the purely temporal nature of the cum-clause, as indicated by tum (27), conlegerat is indicative. (MBA 431)
28-1neque .... impetus exstitisset, nisi .... immanitas niteretur: an unreal conditional sentence in which both clauses refer to the past. Why then is exstitisset pluperfect and niteretur imperfect? exstitisset refers to a momentary action; niteretur to a continuing one.
4respuatur, haereat: jussive subjunctives.
8-9prius .... ante; elegant variation again.
oculis .... suspicione: a neat antithesis.
11ut ipse .... ferat: noun clause subject of est.
12me .... erroris mei paenitet: For the construction see MBA 309.
14maledictis impudicitiae .... coniurationis inuidiam; chiasmus.
16titubanter: The verb titubare, "to reel, totter", is commonly used of the unsteadiness of a drunk. est delapsa (15) has similar unflattering overtones.
17-18non modo .... cohaerebat oratio: another patronising and not particularly subtle dig at Atratinus.
19qui and quod are interrogative adjectives, qualifying furor and uolnus respectively.
24-25coniurationis accusatione: Make sure you can explain who accused whom of what. Austin's references are important.
24-25fuisset .... uoluisset: unreal condition in past time.
25quod: accusative of respect. Latin, Greek and English all inherited from their ancient Indo-European parent the practice of using the accusative case to convey the idea of "as to ....", "in regard to ....", "with respect to ....". It survives in English in expressions such as "heartsick (= sick with respect to the heart)", "footloose (= loose as to the foot)", "fancy-free" etc. The idiom persisted in Greek and in Latin poetry. Early on, however, Classical Latin prose transferred it to the ablative case, e.g. altero saucius brachio, "wounded in one arm". But the old usage survives in, e.g. Cicero's cetera adsentior Crasso (De Oratore 1.9.35), "In all other respects I agree with Crassus." quod is another example. It refers to what has gone before, lit. "in respect to which".
25-26haud scio an: Further to Austin, see MBA 169-170, 197.
28amens: lit. "away-from (his) mind" (a-mens).
28-4fuisset, commaculasset, accusaret, quaereret, putaret, arcesseret: subjunctives in an unreal conditional sentence; accusaret (29) is also subjunctive in a consecutive clause. The pluperfects refer to past time; the imperfects, to present. optaret (2) is subjunctive because it occurs in a clause subordinate to a subjunctive clause neque .... quaereret (1).
29commaculasset: The com- has intensive force.
commaculare = "to stain all over, pollute".
1. cuius: The antecedent is facti.
2. periculum: Further to Austin, periculum is cognate with experiri, "to make trial of, test".
7-8aes, sumptus, tabulae: Each in turn is the subject of obiectum est, which, however, is made to agree with the first of the trio, aes.
9in patris potestate: A paterfamilias had full authority over all those under his control. A Roman male stayed under the control of the paterfamilias even though he might be grown up with children of his own. He was not legally responsible for his actions and could own nothing. In theory the father's power over his free-born descendants was akin to ownership; he could sell or even kill them. The same applied to wives and daughters. Thus unwanted babies could be exposed with impunity. In due course, however, various stratagems were employed by which such children could be emancipated and become full legal persons before the father died. In particular, the killing of adult children was moderated by custom and conscience and, by the time of the Empire, was a thing of the past.
11Further to Austin, the Palatine was the chief of the seven hills of Rome. As it was so near the Forum, it became the fashionable address of the affluent and/or politically ambitious, including Cicero; his rival at the bar, Hortensius; Crassus; the expert in gang warfare, Milo; and Antony. Hortensius's house was subsequently acquired by Augustus and became the nucleus of a cluster of imperial residences. Now you can deduce the derivation of our word "palace".

triginta milibus: On ablative of price, which is basically an ablative of instrument, see MBA 280.

13aediculis: Further to Austin, just as aedes can have a plural form with singular meaning, "house", so can its diminutive aediculum.
14illi and eius both refer to Clodius.
16semigrarit: a shortened form of semigrauerit, perfect subjunctive in a clause of alleged reason. (MBA 484)
17-20Here are two historic cum- clauses, the verbs being consecutus esset (split between lines 18 and 19) and posset (20).
19magistratus petere: Further to Austin, see OCCL 162-163 on the cursus honorum.
22-23quo facilius .... posset: A final clause containing a comparative is introduced by quo. (MBA 102)
23magno: ablative of price.
1-3liceret, exhiberet: subjunctives of unreal condition, the si- clause being suppressed.
5quod: Supply an antecedent id.
loci: partitive genitive.
6Palatinam Medeam: Further to Austin, see OCCL 351-352 on Medea. Geffcken observes that Cicero has used "a technique frequent in the comic tradition, parody of tragedy ... molestiam jolts the audience since it is a prosaic word alien to tragedy ... He then ties together the threads of this parody by the phrase hanc Palatinam .... hanc adulescenti. Alliteration and assonance bind the words together and make them more entertaining and memorable." (15-16)
Further to Austin's introductory paragraph, Mohocks, so called after Mohawk Indians, were ruffians who plagued the streets of London in the eighteenth century. One of their more endearing practices was to roll people down Snow Hill in a tub. Another was to overturn coaches onto rubbish heaps. The equivalent in our own era is the skinheads, or bovver-boys, who first appeared in the late 1960s.
10prudentia: ablative qualifying fretus. (MBA 285)
12qui .... diceret: subjunctive because the clause is sub-oblique.
13prodierit: future perfect.
14maluerit: perfect subjunctive in a sub-oblique clause.
productus: sc. sit.
15ipse per se: The pleonasm gives emphasis. (MEU 440-441, s.v. Apleonasm@, especially '1)
19riuolus: The diminutive has a contemptuous force.
17-20The metaphor of a little stream flowing from a source is well sustained. On the use of metaphors in Latin compared with English, MBA pp. 305-306 is highly instructive.
21gratia, opibus: ablatives, basically of instrument, with nitatur. (MBA 282, note)
22esse .... inventum: Join them up and you have a perfect passive infinitive.
qui .... uellet: the clause is one of characteristic (MBA 503) and also sub-oblique.
25dicerent: subjunctive in a qui- clause of characteristic which is also sub-oblique.
26graues: See the note on 11.23.
27iurati: as in 4.25, perfect participle with active meaning. (KMP 129)
4-5non .... accusatur .... a quibus oppugnatur: a paradox, i.e. an apparently self-contradictory assertion which, on closer examination or (as here) explanation, is seen to contain a truth resolving the contradiction. The opening lines of Charles Dickens's A Tale of Two Cities are a striking example of paradox and of parallelism also. See the note on 22.27-28.