As it is stated in the title, Sense and Sensibility illustrates the clash that occurs when emotions rule our common sense. Austen presents, in a variety of story lines, that romance and social expectations could be detrimental to individuals who allow themselves to be guided merely on these two parameters. Therefore, the story aims to demonstrate that love will always manifest itself the same way to everyone. However, only the strong would survive the "curve balls" that romance throws our way. In all, Sense and Sensibility is a study of how differently people react to the different manifestations of love.
Out several different story lines, one can definitely point out Elinor and Marianne as the ultimate representatives of sense (common sense) and sensibility (emotions), respectively.
Elinor has self-control, abides by social rules, and measures her emotional acumen. She does not allow complexity to ruin her poise. She even tolerates the likes of Lucy Steele and her engagement to Edward. She is stoic and analytical in every way.
Marianne, contrastingly, believes that romance is the essence of life. She transfers her emotional nature to her everyday existence. The result is that she ends up deceived, frustrated, and sick. Eventually, as she recovers her senses, she realizes the foolishness of not quite reading between the lines. In the end, she gets her emotions in check and opts for using her common sense to understand the veracity of the Colonel's intentions towards her.
In conclusion, Sense and Sensibility explores both sides of the spectrum: Common sense in love and emotional reaction. In the end, sense wins. However, Austen also leads us to understand that, in love, all is fair. It is up to us to determine to what point that is a possibility.