Few know that I am the son of a son of a preacher man. That empowers me to pontificate upon the source of thinking. I hope to shed more light on thinking by exposing the root of an incredible ability.
My observation is based on the amazing fact that we are very good at recognizing patterns. We can see them not only on a plane but also in 3D space sequenced through time. Can you catch a ball? Even those who cannot catch one can usually follow one through the air. It is like we have a simulator running in our brain that holds a model of the outside world. We run a scenario in it and quickly determine where it will be based on seeing just the initial conditions. When a ball is tossed at you, your brain immediately begins tracking the trajectory. It send signals to your arm to position your hand into the balls path and then to grasp it at the precise moment it is within reach. Naturally the slower the ball is coming at you the easier it is to catch.
If you look at the maze you can easily see where the entrance and exit is. But hidden in the pattern is the path between the two. Only by tracing our steps through it can we hope to find that path. This is also true regarding the path to understanding how we are able to think. Our use of a built-in simulator able to predict the complex trajectory of a thrown object is more than just a practical toy for a thinking machine.
But what came first, our ability to model or our ability to reason? I can see how the ability to model could have evolved initially. Then reason developed. This allowed us to see the uses of reason and predict predication!