In Episode 5 of Sense8, what I believe will be the show’s main theme is made explicit by one of the 8. As Kala takes her wedding vows with a man she does not love, she says, “We shall share love, share the same tastes… share our strengths. We shall be of one mind.”
This quote ties up many of the experiences which the Sensates (which I have learned is the proper term for them) have been having as their mental bonds strengthen. Not only do they share tastes, such as when Kala takes a bite of shahi dukta, and Nomi’s coffee suddenly tastes “like a sugary dessert,” but they also share other sensations. When Sun gets kicked in the stomach, Lito feels the pain.
On multiple occasions in other episodes one of the Sensates has been in potentially lethal trouble and another has lent their strength to the one in need. When Capheus was being beaten up by some thugs Sun’s martial arts training allowed him to defend himself.
In this episode the Sensates draw closer together and begin to see each other more frequently in addition to sharing tastes and strengths.
As this happens their lives also begin to parallel one another. Sun has to decide whether to sacrifice herself to save her father and brother as Capheus signs on with a crime lord to get medicine for his dying mother.
All of this contributes to the idea that the Sensates are literally of one mind, and are experiencing their lives together as one. In a larger sense, the fact that these 8 diverse individuals who often can’t even speak the same language (except when sharing strengths) are able to form a group and each strengthen the other makes an argument in favor of diversity strengthening a society. Additionally, the fact that they are having the same experiences — both as a result of their bond (sharing tastes) and independently of this bond (making parallel life choices) — makes an argument that no matter what a person’s appearance or background everyone is equal and has equally valuable experiences.