There has always been a conviction within the Church that genuine vocations come from God, and that it would be criminal to block such vocations. The roots of any vocation lie in our having been created by God. Every potential in us comes from God's hand and every call, whether to a task, a ministry, a kind of life or a special mission, arises from God's calling out of nothingness into being the individuals we are.
Christian baptism includes the potential of the call to the sacramental priesthood.
And since baptism is the same for women and men, both receive the same implicit and remote calling to the sacramental priesthood. The call to the ministerial priesthood was formerly often understood in a rather magical and simplistic way. God was imagined to literally pick out candidates according to his inscrutable decrees. I remember hearing the following story during a retreat in the major seminary. Before the creation of the world, God called his angels together and gave them a preview of everything he was going to make, including the human beings of all future generations.