We spend much of our lives attempting to get other people to do things we want them to do, with varied results. Have you wondered why we are highly successful at times, and why we fail? Also, why certain people are far more successful than others?

The Ancient Greeks had a separate field of study for this art - the art of Rhetoric - which deals with how we can use language to persuade others. The reference to language is important, because in the end, language forms the primary means by which we try to convince others.

Aristotle specified three sources of persuasion in his treatise 'On Rhetoric', and they still remain highly relevant today:

Ethos - stands for ethics, integrity, honesty, transparency - and has everything to do with the character of the person attempting to influence. Given the same argument for accepting something, we are much more likely to be influenced if they come from someone who is credible in our eyes - either because of his or her moral standing or expertise on the subject. Conversely, all the logic and correctness of a piece of reasoning or advice counts for nothing, if we fundamentally do not trust the speaker or attribute bias or vested interests.

Pathos - appeals to the audience's emotions. This can be understood in two ways- At one level, it is a play on our heartstrings. Evocative language, drama, tone, pitch and modulation, use of vivid similes / metaphors/stories / humor to drive home a point - all of these bring in Pathos into an argument. These are especially powerful in oratory, where a skilled public speaker can heighten the emotional response of an audience to a point where the words and logic don't matter anymore. In contrast, a perfectly credible speaker using sound logic, but with no pathos in the delivery can lose an audience in no time (think of a brilliant but boring college Prof, for instance).

However, Pathos runs much deeper than mere embellishment. Pathos is the etymological origin of our words Sympathy & Empathy. In this sense, Pathos implies concern, care - a connect with the audience. When the listener believes that the speaker demonstrates genuine care (for the interests & well-being of the people he is trying to influence), the listener is much more likely to get influenced.

Logos - stands for logic, rationale and reasoning. If the buy-in you are seeking is built on strong logical foundations and appears rational and reasonable to the listener, you are more likely to succeed.

I believe there is also a clear hierarchy / sequence in the use and relevance of the three sources. Ethos is foundational - almost a hygiene factor. Fundamentally, if you are convinced that your boss is a 'bad-un', or if your peer will knife you behind your back, you are going to discount everything they are going to say and do. Loss of trust and credibility is fatal - to all relationships.

Pathos comes next, especially in its second (and to my understanding deeper) sense. Your project leader may be credible and capable, and may be fairly principled. But if you believe that he or she really doesn't have your best interests in mind (at heart?), just doesn't care, is essentially self-seeking, then his / her influence on you is going to remain limited.

Logos comes last. With our rational / scientific training and our 'professionalism at work' ethic, we seem to prize logic above all. However, think of it this way - when your close friend or relative (say your grandfather) asks you to do something which appears illogical to you, you may comply, purely out of respect for the pathos in the relationship; but when someone who you believe doesn't care about you asks you do something that is perfectly logical, you feel an inner resistance. Any compliance will be grudging, at best.

So the next time you are trying to convince a group of people, and you feel the resistance - check the pathos element (we shouldn't have trouble with the Ethos and the Logos parts.)

I have personally seen this at work when as consultants, we tried to influence change in organizations. We were extremely sound on logic, but the clients / projects where we had the greatest success were those where we managed to overcome the Credibility gap and the Care / Concern gap. And we could never do this on our own as consultants; it always required strong involvement from a credible and concerned client senior management to pull it off.

Lastly, the sources of influence have a strong connect with the concept of leadership. After all, a leader is one who has followers. You could reflect on the really good leaders you have come across and try to understand the combination of all three sources of influence they used. Of course, there are plenty of examples of leaders who misguide audiences into following them (think politicians, think dictators who use the emotion of fear, think media / advertising and so on). Plato, Aristotle's teacher wrote another treatise on 'Good' and 'Bad' Rhetoric. But that's another story…