There are, apparently, voluntarisms. Voluntarism means the priority of the will over the intellect, or of want or desire over reason.
Voluntarism in theology means that God determines, and because he determines, the thing is right. This is a God of mystery. He is fundamentally unknown because the rationale for his determination can never apparent to us. It does not affirm that God has reasons we cannot know, it denies that God has reasons.
Intellectualism is the alternative. God determines because it is right to do so, and in some way it is can be apparent to us. This is not to say that God is comprehensible, but that there is some way for us to make sense out of what God determines. Intellectualism can appear to suggest that there is some necessity in what God chooses.
What we should keep in mind is that in God nothing is prior. We are not talking about a will that is prior to intellect or an intellect that is prior to will. What we are talking about is what we can and cannot know, and what, correspondingly, our relationship is to God. Voluntarism tends to foreground mystery and power. Intellectualism foregrounds reason and goodness.
There is voluntarism in anthropology. The priority of the will over the intellect is the mark of voluntarism. We do what we want, not what we know. We ought to order our desiring to what we know, but our desire is what determines. Intellectualism would be the priority of the mind and knowing.
I think in complex and responsive beings, it makes sense to be voluntarists. I join Augustine, Anselm, Scotus and Calvin, along with Pascal in that. The heart has reasons of which reason knows nothing. But in a simple being such as God, who is never responsive because he is impassible, then it is merely a question of our relation to him. Nothing in God is prior. The question is how we know and understand him, and in this respect I oppose voluntarism. Intellectualism is the Platonic option.