Originally posted by Xprobe:
my question is - how can one practice vajrayana without a solid foundation in mahayana?
If one wish to practice vajrayana, he must have the core of mahayana which is bodhicitta, if not, he will not succeed.
As mentioned, vajrayana is part of the mahayana buddhism, just that the practice is different, it has a lot of convenient method that enable the practitioner to become enlightened very quickly.
But if the person's motivation is for himself only, don't even have the worldy renunciation and breaking the vajrayana precepts, he will go to the lower realm very quickly also.