3、因果论证式：首先说明对象造成的一个原因，然后引出对于现实生活中的影响和作用，最后对上述论证进行加固或者补充（对于论证中的可能漏洞进行弥补）。同样我们用范文向大家示范：

235. "Most people are taught that loyalty is a virtue. But loyalty whether to one's friends, to one's school or place of employment, or to any institution is all too often a destructive rather than a positive force."

（范文）

Once I participated in a speech given by a famous local entrepreneur, who rose from exactly bare hands. The word branding me most is "loyalty", the very one we hardly dabble and almost reaches the edge of oblivion but instead no negligence is deserved. How can this concept bridge the relation with the huge lope of his life? Loyalty makes one stick to a goal without any fickleness until achievement, which has won a lot much for him including friendship, dependability and love. Ironically, today's people are becoming more and more "sagacious" to plan for themselves better, holding the principles of choosing best, moving fastest, and snatching most; in other words, loyalty is degenerated into a totem of stubborn stereotype inadaptable for the society of profits first.

Is that modern theory "true"? And what about the success of that admiring entrepreneur? Something people primarily should understand is the indispensability of credence active among human community for the perpetuity of humanistic relationship, which to a large extent stems from this loyalty. No exaggeration I have made to emphasize its paramount function to personal survival. Either from the fable or history we can learn the lesson. But now I would like to continue to elicit the example of that manager upstairs. When he was still an employee working for this consult company (before he climbed up to the top rung of the company committee), there was a huge recession leading to a total profits declination in this operating domain, which in the end resulted in almost all elites of the company making a job exchange except him. His persistent determination was for nothing but loyalty, of his indebtedness form his boss, of his enamored undertaking tolerating for no intermittence, of his adherence to goal successful for sure. And the fact tells us everything, as each audience can see, he did.

Not only to individual the quality of loyalty can push one into the acme of his career following with winsome reputation, but also to community the crucial pillar to support the sculpture of serenity goddess. Once separated from the loyalty, credence is also accordingly right away crushed under the wheels of history cart, and then the concomitant condition can be imagined as this: various associations would certainly collapse under the circumstance deprived of dependability: each one discredits the motive of action from anyone else; talking is evolved into a serial of satirical assaults; compassion sounds more like a snicker, and ultimately ineluctably the human society is degraded into a state of depravity. Is this the community we each of us want to live in? Is this the situation we each of us want to make realized? If your answer is negative -- just like mine -- then please retrospect your conscience to retrieve this precious virtue of "loyalty".

While the merits of loyalty have been corroborated here so strongly, admittedly, however, loyalty applied only to the legitimate partner or purpose, not involving the malign ones, somehow or other the effect will surely arrive at the surprising reverse. For instance, from the point of penal law, excluding the major miscreants who abet the underlings to commit guilt, the adherent to follow his felony, even if he never directly joins in the crime doing on the spot, but as a result of his ancillary work, he should also assume a certain quantity of the great responsibility, which might mean him a ferocity of being disenfranchised, or at the same time to enjoy his later few years' prime time in the jail. The tragedy is so natural for most of us that admonishing clock is being struck; the high time for us to wake up from the sequacious loyalty is coming.

Overall, the virtue of loyalty is one of the fundamental factors heading for our prosperous tomorrow, despite its contain of some potential stygian side effect turning to the malicious dimension, yet no doubt it deserves to be advocated to learn for the brace of the beneficial development of both single person and gross society. Like the rationale of any medicine we take normally, no one of us will stop to ingest pills of penicillin just because of its possible allergy to some particular patients, after all its application and efficacy is indelible.  

（来源：网络）