Board Thread:Lore Discussion/@comment-11276487-20130728170148/@comment-10207438-20131126214831

true, but after the battle of red mountain Jurgen Windcaller realized they were abusing their gift, and blah blah blah, now the only way they can learn the Thu'um is if they learn from the Greybeards, who are 'mostly' Pacifistic, so they're not really going to teach you how to use the Thu'um for war, which is why Ulfric had to leave the Greybeards so he could use his Thu'um for war.