The pressure is on. David Cameron’s closing speech to his party’s conference will be his eighth as Tory leader, and his MPs and grassroots supporters are hoping that he can top Ed Miliband’s effort in Brighton last week. While they are bound to be wondering whether he too can come up with two or three potentially game-changing announcements, the fact is he’ll inevitably be judged as much by his presentation as his policies.

If previous years are anything to go by, however, Cameron is likely to pass this particular test with flying colours – and not simply because he possesses a modicum of stage presence, a good memory and often pitch-perfect delivery. It’s also because, with more than a little help from his speechwriters, the Conservative leader is something of a dab hand at the ancient arts of rhetoric and oratory. What better way to explore his techniques, then, than through the classics?

The first thing anyone reading about rhetoric learns is that ethos, pathos and logos aren’t the names of the three musketeers but rather the primary modes of persuasive appeal outlined by the Greek polymath, Aristotle. Ethos is about establishing credibility; pathos is forging an emotional connection; and logos is reasoned argument.

As far as ethos goes, Cameron’s main concern, right from the start, has been not so much to assert his authority as to stress his authenticity. In order to scotch the pervasive notion that he is little more than a slick, metropolitan posh boy, the Tory leader characteristically emphasises both his traditional values and his simultaneous willingness to confront his party’s prejudices. He routinely recalls the adversities his family has faced. Occasionally, he resorts to the “this is the real me so who needs notes?” trick that helped win him the leadership in the first place – although that probably pays fewer dividends now that the leader of the opposition has got in on the act too.

Still, being PM makes ethos much less of a problem since it derives as much from status as it does from character. Mind you, the former provides plenty of additional chances to prove the latter, not least because of all the opportunities it gives Cameron to show how he’s standing up for Britain. Expect more of the same this time.

Cameron tends to seek pathos in very predictable places: his children and his parents – and their disabilities – being the most obvious examples, although they are sometimes joined by “real people” he’s met or who have written to him. For all that, Cameron is actually pretty cautious about trying to conjure up melodramatic images, or enargia.

Cameron is well aware, however, that an emotional connection can be achieved by laughter as well as tears. His jokes are almost always corny and contrived, although less so, interestingly, when he’s feeling brave enough to tease his own traditionalists. He even tries now and then to be a touch risqué – or at least what passes as such in Conservative circles. And for someone often thought of as preternaturally arrogant, he actually does self-deprecation pretty well.

That said, Cameron’s most consistent and characteristic effort at pathos revolves around his appeals to optimism, particularly (though not exclusively) in perorations ladled with anaphora (one sentence after another beginning with the same word or phrase) that sometimes blur not only second and first person, plural and singular, but also party, voters and nation.

What is noticeable, however, is that since moving into No 10, Cameron has put a lot more emphasis on logos, as he did last year in Birmingham when he made a sustained case for the need to get this country fit for the “global race”. Yet even when making a conspicuously reasoned argument, Cameron still relies just as much on supposedly self-evident truths as on the detailed (sometimes statistical) evidence he increasingly inserts into his speeches.

In the end, though, we can’t say for sure what Cameron will come up with this time round. After all, to the truly skilled orator, decorum (appropriateness) and kairos (timeliness) are crucial considerations. Each and every party conference speech presents a slightly different challenge – Cameron will almost certainly rise to this one.