It is very important to know whether or not what you are holding is a block of wood.

For instance, you might be holding a grenade whilst erroneously thinking that it’s a block of wood, and I need not explain the obvious unpleasantness of this dilemma.

Luckily, there is a book you can buy to solve all of your wood-related difficulties.

Is this wood? No. Is thiiiis wood? No. Is this wood... YES!

Thank you, R. Bruce Hoadley, you have made the world a more identifiable place.  Using this book I have gone from “speculative” to “certain” that the fence in my back yard is in fact made of wood.  I feel informed, I feel energized, and I feel exited about life and wood.