I initially thought I would answer this question first because the answer seemed so strightforward and simple; but thinking about it caused me to pause. The more I know of vocations the less clear any answer about them seems to be.
For example, one might think that the vocation of St. Thérèse was that of a Carmelite Nun. But late in life she is quoted as saying, "My vocation is love, love at the heart of the church." She spent much of her vocational life searching for her vocation.
So, the real answer to this question is that in my limited understanding, the contemplative life is an aspect of a wider vocation--that of religious, or married. I don't know if it exists by itself as a vocation, but it seems that every contemplative I'm aware of had a larger view of their vocation, that contemplation was part of what they did and were, but not the entirety.
So, this unsatisfactory response is as close as I can come to a definitive answer. Sorry, but this requires one with far greater knowledge and understanding of the meaning of vocation than I have to answer it. I can only answer from one side and say that it certainly can be part of a vocation. As to whether it constitutes a vocation in and of itself, I will trust wiser minds and those with more extensive knowledge to inform all of us.
