Please note that the online Mesilas yesharim we\I have been using until now, has been taken temporally off line. However, thanks to melech who posted more than one copy of the Mesilas yesharim, I was able to find other hebrew and english copies online. click here for hebrew and here for english.

In this chapter the Ramchal discusses three principal divisions of Separation, those involving pleasures, laws, and conduct.

In regards to those involving law I found this account (from the gemora) fascinating:

QUOTE (mesilas yesharim ch. 14)
As Mar Ukvah said (Chullin 105a), "I am to my father as vinegar derived from wine; for my father, if he would eat meat today, would not eat cheese until tomorrow at the same time, whereas I, though I would not eat cheese at the next meal, would do so the meal following that." Now there is no question that the practice of Mar Ukvah's father does not constitute the law in the matter, for if it did, Mar Ukvah would certainly never have gone against it. It is just that his father was stringent in his Separation. And it is because Mar Ukvah was not on a par with his father in this trait that he compared himself to vinegar and his father to wine.


Although the Ramchal brings this story to illustrate that we are not talking about forbidden things, one can also see from this story that although Mar Ukvahs father kept this chumrah, Mar Ukvah himself did not.