Folk pull apart the butterfly to see how it works. Divisions of the human being are made for the purposes of scientific study. There are always flaws in this approach to study, in that each part works in with the other as an organic whole.
When do we ever purely think, purely feel or purely will? It is always a matter of cooperation between faculties.
Viewing the human being as a lot of fragmented parts is fundamentally wrong to begin with- an unhealthy soul conception. We are (or should be) after all, a functioning whole.
Rudolf Steiner uses the word "thinking" in a specific way. What is spoken of colloquially as "thinking" is not thinking but a parade of ideas.
The statement by Dr. Steiner that animals don't think is considered controversial by some. Steiner did admit that animals deliberate. A wasp deliberates, or a beetle which really doesn't have much that you could call a brain, deliberates. The great wisdom that a beaver displays in constructing dams, lodges and canals to transport logs, is something that the beast "sucks in" from outside of itself- from the Cosmos according to Steiner. But still this must also require some deliberation by the animal itself.
The difference between the animal and the human being is that the human reasons in full waking consciousness. The conditions of driving a manual car and "automatically" changing gears, or "automatically" touch typing as you read a text don't really come under the heading of "thinking". In fact if you become conscious of your fingers moving to each key one by one, you slow right down- so thinking about the process doesn't help. The human being is not stuck in one area of reasoned thought that goes around and around- like a beaver building dams season after season. Of course, some are stuck on this merry-go-round.
There are other ways of knowing besides thinking. In fact human beings in the ancient past had an instinctual knowing that enabled them to build civilizations that rivaled our own in technological marvels.
In the realm of thinking we can become conscious (that is why we have the capacity for freedom in thinking), in the feeling life we live in a dream and in willing we are in a deep sleep.