Genuine commonsense reasoning

 I propose 2 quite simply distinguished types of commonsense reasoning. Lets call them A and B. My point is that B is tougher to do than A, and truly exploits the diversity and resourcefulness of the mind that commonsense reasoning demands (Minsky, The Emotion Machine).

Lets see type A commonsense reasoning. If there is no petrol, the car wont run. If you close the gate the car won't be able to enter the building. Now, in the first case, petrol is MEANT TO run the car. It is a definitive property or role, as one might say, to run cars. Gates are MEANT TO allow/disallow entrants. So, here the reasoning which is done (thinking of the implication) is in line with what the key entity is meant to do - in line with the definitive role of the entity. So it is easier to do this kind of reasoning. Whatever be the knowledge representation and storage mechanism in the mind, the fact that petrol is required to run cars is stored very "near" to the definition or identity of the entity 'petrol'. 

But now consider something else (type B). Suppose a tree falls on the road, then a car won't be able to move ahead. Here, this calls for genuine commonsense reasoning since it is not a definitive function of trees to "block things in a fallen state". That's not what a tree is (primarily) meant to do - it's meant to purify the air, provide shade, flowers, fruits etc. So this reasoning involves abstractising a tree as a general big mass of solid, which if comes in the way of something, can mostly prevent it from going ahead or block it. This, I guess is a more genuine form of commonsense reasoning since it involves representing/seeing things in ways which are not their key features but are the quintessential feature with regard to the situation/context at hand. That shows agility and a non-stereotypical fashion of thinking of the mind.