Simplify the following text for a Grade 10 native English-speaking person.
Original: He called these the `` Three Principal Aspects of the Path '' , and asserted that it is on the basis of these three that one must embark on the profound path of vajrayÄ na Buddhism .
Simplified: He called these the `` Three Principal Aspects of the Path '' , and said that it is on the basis of these three that one must embark on the profound path of vajrayÄ na Buddhism .