I noticed your old thread on going from HIT to volume. I like HIT but there are times when, for instance, I will do something like 5 sets of 50 reps for light barbell curls and 10 sets of 50 reps on light triceps pushdowns. I will do the same for shoulders for up to 50 reps and back and chest will be the same thing. The weight stays the same but as the sets progress, the reps tend to go down.
It all depends upon how I am feeling physically and mentally. While I do think there is no one "correct" way to train, I also think there are plenty of ways to screw yourself up by training wrong. I have never gotten hurt using light weights with lots of reps but then I've also never gotten hurt going heavy for low reps and sets. I train to look and feel as good as I can.