Aposteriori is a collective of voices that all believe in one thing: the world can ultimately be changed for the better by positivity, inclusion, community, acceptance, and empathy.

A posteriori is from Latin ā posteriōrī, which means literally,

"from what is later." 

It describes knowledge based solely on experience or personal observation.

You can make all the assumptions you want about the world a priori. 

But at the end of the day you have to experience it:

a posteriori.

To let what is later, show you what you need to know, see, and feel.