I am not able to understand these axiom and statements by hilbert.
" theorem 8. If two straight lines a, b of a plane do not meet a third straight line c of the same plane, then they do not meet each other.
For, if a, b had a point A in common, there would then exist in the same plane with c two straight lines a and b each passing through the point A and not meeting the straight line c. This condition of affairs is, however, contradictory to the second assertion contained in the axiom of parallels as originally stated. Conversely, the second part of the axiom of parallels, in its original form, follows as a consequence of theorem 8."
Please explain what he's trying to say ?