Love is certainly evasive in a story where misery and fate meet social limitation, particularly when they all come together in one same character; one who is born with a magical, yet, dangerous ability that could either make him or break him. This is the case of Grenouille; an individual of the lowest caste in his society.
However, a meditation on love concedes the analysis of symbols and situations that may lead to the identification of one or more forms of this sentiment. The story does not present love to us in a specific way, however, it evokes the reader to realize the supreme need of it. In other words, had there been love present in his heart, and if the world where he lived had not been so foul, and empty, Grenouille's life, as well as those of his victims, could have been spared.
It is suggested in the story that this scent with which we are born is so powerful that it bonds us as a race; but scent alludes to the human soul. Grenouille has no scent. This is almost an allegory for having no soul. Hence, he cannot feel, he cannot care, and he cannot even love himself. He, however, possesses the ability to create something more powerful than the personal scent; a perfume. Something that is artificially made to evoke feelings in people. This, he can create, even if it takes him to murder others to get the "right" scent in.
When he presents this creation to the world, the world goes mad for it. This is because this perfume fills every void that a world without true, magical love has in their hearts. When they feel the first sense of it, havoc breaks loose. People go mad about it because it wakes up the senses and makes them feel in more intensity the many sensations that love makes us feel. However, their bodies cannot comprehend these emotions, and they literally go to the point of basic animal instinct as a result of how this elixir makes their life so out of this world.
Therefore, the novel shows how everyday life, the turmoils of existence, and the daily battle for survival render us unable to feel the true manifestations of love. Life dulls us, but love makes us shine. The dullness and darkness in Grenouille's world basically shows a world without emotion, without love, and without magic. When his potion is created, all these needful things come out in such an intensified way that people literally lose their minds. Hence, feeling love in one's life--whatever kind of love--is essential for survival. That is, basically, what the entire issue with the perfume entails.
Thank you your answer has been very helpful.