There are only two forms of thought.
The first is expressive. This occurs regardless of whether the thought held internally or presented to the world. These thoughts reveal what you value, at least in the moment. If you are a considering a loved one, you are expressing your value of love. If you are arguing, you are expressing your value for anger.
The second is of learning. While it can be said that inquiry is expressing one's value of knowledge, this is more subtle. Learning is ascertaining what is valued. Someone may attend a beginning art class to determine if the skills of artistry are valued enough to express through study of the field. Learning is the passive receiving wisdom from the Universe.