We consider Functional Thinking as _second-order thinking_.
Some call to this type of thinking as 'critical thinking', one that challenges a learner to _analyze_ that which they are focused on. But it's more than that, it also challenges the learner to construct new models, to _formalize_, in order to guide future action.
This functional thinking allows us to be reductive _and_ constructive using logical models. This intellectual capacity has be instrumental for many of the advancements in our modern society.
While we associate behavioral thinking with the brain's default network, we notice that functional thinking creates the eustress that helps develop the executive network.
Descartes opened the door to deductive thinking, and it was Kant who opened the door to our capacity to formalize using internal cognitive models, which he called a 'schema' guiding a path to education that sought to develop capacity for functional thinking.
Our schools often only seek to develop functional thinking for its more 'advanced' students, those who have been tracked into higher-level classes. The unspoken assumption is that this thinking is only needed to develop a management class that defines the work outcomes for others, those thought to be only capable of following instructions – a model design to support an industrial economy.