If the world had no beginning in time, then the history of the world would have traversed an actually infinite number of previous moments.
It's impossible to traverse an actual infinity.
Therefore, the world had a beginning in time.
Moreland defends the second premise by saying that it's impossible to think backwards (in your mind) over previous centuries to cover the totality of time.
{ 1 } - True
{ 2 } - False
Any past moment you consider must have existed only a finite number of years previous to the present moment. We can count backwards in time: "now," "1 century ago," "2 centuries ago," "3 centuries ago," ... But we can't count down from infinity to the present time: ..., "3 centuries ago," "2 centuries ago," "1 century ago," "now." We'd have nowhere to begin!
If the world had no beginning in time, then the history of the world would have traversed an actually infinite number of previous moments.
It's impossible to traverse an actual infinity.
Therefore, the world had a beginning in time.
Moreland defends the second premise by saying that it's impossible to think backwards (in your mind) over previous centuries to cover the totality of time.
{ 1 } - True
{ 2 } - False
Any past moment you consider must have existed only a finite number of years previous to the present moment. We can count backwards in time: "now," "1 century ago," "2 centuries ago," "3 centuries ago," ... But we can't count down from infinity to the present time: ..., "3 centuries ago," "2 centuries ago," "1 century ago," "now." We'd have nowhere to begin!