If I loved you less, I might be able to talk about it more. But you know what I am. You hear nothing but truth from me.

One of the most important qualities in the heroes of Jane Austen’s Emma is the ability to speak openly, honestly, and without flattery or exaggeration. Mr. Knightley embodies this quality to the max. He always says what he means, and he never minces his words. When it comes to the most important things in his life, he will state his truth plainly. His admission of love to Emma means more than any bit of flattery from men like Mr. Elton or Frank Churchill because Mr. Knightley’s admission is “nothing but truth.” Emma can trust that Mr. Knightley’s love for her goes far beyond admiration or attraction. The depth of his love for Emma cannot be articulated with fancy phrases or long compliments – instead, he relays to her only the simple truth of his feelings, and that is more than enough for Emma.

I never hear better sense from any one than Robert Martin. He always speaks to the purpose; open; straight forward, and very well judging.
 

While Emma herself is the heart of the novel, Mr. Knightley is its moral center. Although he isn’t right about everything, he can often be trusted to have a compassionate and rational opinion on most matters. If he speaks highly of someone, like Robert Martin in this case, it often means that this character is a truly good person. A strong theme in the novel is the preference for open, honest communication over secrecy and manipulation, and Mr. Knightley embodies this trait. Knightley can be trusted to see the truth of a person or a situation, and since he believes that Robert Martin is also an excellent and honest young man, the reader should take up this belief as well.

There is one thing, Emma, which a man can always do, if he chooses, and that is, his duty; not by maneuvering and finessing, but by vigour and resolution.

Mr. Knightley embodies everything that he believes man – or gentleman – should be. He is not only caring and compassionate but also serious, responsible, and authoritative. He always stands against manipulations and “finessing,” which Emma, Frank Churchill, and less mature characters constantly take part in, and knows how important it is to be dutiful and morally sound. In this passage, Knightley is hinting to Emma that Frank Churchill is not a responsible or mature man, something that Emma also senses but does not want to admit. But unlike the rest of Highbury, who are too polite and deferential to say a bad word about Frank, Mr. Knightley doesn't hesitate to tell the truth.