Sometimes related to the Four Terms Fallacy, this is treating an abstract idea as a physical object. For example, "Eating ice cream feels good. Therefore, we should give ice cream to criminals, so they become good." This assumes that "good" is a thing that can be measured and which is a physical property of ice cream in fact "good" is an unmeasurable and quite subjective concept. Similarly, you can't go down to the store and pick up a can of consideration or a box of blue; they are attributes of things, but do not exist independently of them.
A variation is treating a thought experiment as a physically workable one; for example, imagining that one could use Schrödinger's box apparatus to actually cause quantum superposition of a cat.
- Socrates' argument against hedonism in Gorgias is pretty much entirely composed of this. Especially memorable is the bit where he gets the guy to agree that punishing criminals is correct, and that therefore one who punishes does good things, and therefore a criminal has good things done to him and his lot is made better.
- Shown to occur in educated college students. In an experiment, students considered a hunter-gatherer tribe which hunted turtles for their meat and boar for their bristles to be strong hunters and a tribe which hunted boar for their meat and turtles for their shells to be tough fighters, even though slaying a turtle and a boar for either reason is equally difficult. The characteristics of the animal in question somehow "essentially" flow into the tribe. Though another possibility is the students attributed this fallacy to the tribes themselves. Some cultures have similar beliefs, feeling that certain animals (or sometimes humans) could give them their unique abilities when eaten.