progression from one to the other to me.
But as I understand it that also means that they believe there is no real meaning to life, other than what each individual makes it... and there is no "right" or "wrong" answer... it is relativism in the extreme.
The meaning Hitler gave to his life would be just as valid and true as what Mother Teresa of Calcutta decided was the meaning to life... and every other person would make up their own moral code, or decision that there IS no moral code whatsoever.
Perhaps that type of thinking explains those who favor abortion "rights"... the feeling that having a "right" to rip the arms and legs off of an unborn baby is a "good" thing... or even to allow a born baby, or a fetus outside the womb as Barack Obama referred to them to languish and die for any or no reason whatsoever, just based upon the whims of the mother at that particular point in time.
Existentialism (~ 8 min)
https://youtu.be/YaDvRdLMkHsEdited by JeffB at 18:39:35 on 02/10/19