He's definitely meaning something along the lines of 'plausible' - 'the possible' here means 'what we consider possible'. I think the quote makes that obvious

He's definitely meaning something along the lines of 'plausible' - 'the possible' here means 'what we consider possible'. I think the quote makes that obvious though. If you hammer everyone's parse errors out of snappy quotes they end up pretty awkward and dull.