Well, it's a bit silly to quote SSC (a blog that rewrites basic philosophy so STEMheads can think they invented it) for a definition of "slack".
If you'd simply omitted the bracketed clause, perhaps your comment might have been useful!
SSC wouldn't have a niche if they could get concepts across without a bunch of obscurantist bullshit.
People criticize SSC because they're like "uh leave it to the REAL experts", but A) it's just opinions and B) the 'real experts' are unreadable, so I'll continue to ignore them while occasionally checking out astralcodexten.