簡單的說,煩惱障就是障礙有情出離分段生死 [delimited existence (paricchedajarāmaraṇa);
delimited saṃsāra] 的煩惱,也就是見惑[the
affliction abandoned through vision] 與思惑[the
affliction eradicated through cultivation]。由於這兩種煩惱不能斷盡,使得眾生無法出離三界生死苦;這就是煩惱障。此謂二乘法中所說三縛結[the three fetters] 及五下分結[the five lower fetters]、五上分結[the five higher fetters] 也,即是大乘法中所說一念無明[the nescience in a single thought; the ignorance in a single
thought] 四種住地煩惱── 所謂見一處住地[entrenchment of identity-view]、欲界愛住地[entrenchment of attachment to
objects in the desire realm]、色界愛住地[entrenchment of attachment to things
in the form realm]、有愛住地[entrenchment of attachment to objects in the formless
realm] 等四種煩惱也。煩惱障之四種煩惱,障礙學人證解脫果,令諸學人不證三解脫門,故名煩惱障。
煩惱障就是我見[self-view;
the view of self (atmadṛṣṭi)]和我執[self-attachment;
attachment to self],也就是見惑和思惑,也就是五下分結和五上分結。(其中三果人斷五下分結:也就是三缚結中的我見、疑見、戒禁取見;再加上欲界貪、欲界瞋就是五下分結。而五上分結是色界愛、無色界愛,掉舉、我慢、無明。)
而所知障是因為對法界實相正理的無知,導致無法證知法界的真實相,無法證知一切法的根源,因此而無法成就佛道,這就是所知障;說的就是對於法界實相的所知不足,所以成為佛道上的障礙,故名所知障。所知障的真實意義,是說由於對法界實相所知不足,所以進修佛菩提道時就被障住了,就無法了知大乘佛菩提道的見道內涵了!就無法了知成佛之道的內涵與次第了,這才是所知障啊!是對實相所知不足而被障礙,不是說在世間法上所知太多、知識太多了,所以障礙你的修行。因此所知障就是《優婆塞戒經》中說的智障 [the hindrance of knowing],也就是《勝鬘經》中說的無始無明[beginningless ignorance] 等恆河沙等數上煩惱[the
higher afflictions; virulent afflictions],那是一切辟支佛和聲聞阿羅漢所不能斷的!聲聞阿羅漢與辟支佛只斷了煩惱障,並沒有斷所知障(也就是智障或稱無始無明塵沙惑[mental disturbances brought about by the immense
variety of details requiring attention in the task of saving sentient beings])!只有如來世尊斷了煩惱障與所知障!