Full Idea
It is crucially one's view of the status of the future that makes one a tensed or a tenseless theorist.
Gist of Idea
It is the view of the future that really decides between tensed and tenseless views of time
Source
Robin Le Poidevin (Past, Present and Future of Debate about Tense [1998], 5)
Book Reference
'Questions of Time and Tense', ed/tr. Le Poidevin,R [OUP 2002], p.37
A Reaction
If you believe in the reality of the future, you are an eternalist and like the B-series. If you deny the existence of the future, you must opt for Presentism or the Growing Block (depending on the status of the past).