Did I identify an uncoined fallacy?

The way you've syllogized and described your so-called "amount" fallacy does indeed refer to either composition or division fallacy - hardly a new discovery.

You responded: "there's no whole, and no part", and yet you've named it the "amount" fallacy - so it appears contradictory.

• Some amounts of X are bad (part)

• Some amounts of X represent all amounts of X (part-to-whole)

 All amounts of X are bad (whole)

Fallacy of Composition

Description: Inferring that something is true of the whole from the fact that it is true of some part of the whole.  This is the opposite of the fallacy of division.

Logical Form:

A is part of B.

A has property X.

Therefore, B has property X.

Example #1:

Each brick in that building weighs less than a pound.  Therefore, the building weighs less than a pound.

Example #2:

Hydrogen is not wet.  Oxygen is not wet.  Therefore, water (H2O) is not wet.

Example #3:

Your brain is made of molecules.  Molecules are not the source of consciousness.  Therefore, your brain cannot be the source of consciousness.

Explanation: I included three examples that demonstrate this fallacy from the very obvious to the less obvious, but equally as flawed.  In the first example, it is obvious because weight is cumulative.  In the second example, we know that water is wet, but we only experience the property of wetness when the molecules are combined and in large scale.  This introduces the concept of emergent properties, which when ignored, tends to promote magical thinking.  The final example is a common argument made for a supernatural explanation for consciousness.  On the surface, it is difficult to imagine a collection of molecules resulting in something like consciousness because we are focusing on the properties of the parts (molecules) and not the whole system, which incorporates emergence, motion, the use of energy, temperature (vibration), order, and other relational properties.

Exception: If the whole is very close to the similarity of the parts, then more assumptions can be made from the parts to the whole.  For example, if we open a small bag of potato chips and discover that the first one is delicious, it is not fallacious to conclude that the whole snack (all the chips, minus the bag) will be just as delicious, but we cannot say the same for one of those giant family size bags because most of us would be hurling after about 10 minutes of our chip-eating frenzy.

Tip: It is worth a few minutes of your time to research the topic of “emergence.” 

My first thought it is fallacies are not dependent on premise being true or not. Your form of the fallacy is actually an argument. If premise 2 is false, then you just have an unsound argument.

More generically, the fallacy is actually in making no useful distinction between "some" and "all," or two points on a continuum, when such a distinction is warranted. This is the argument of the beard .

If someone were to argue that some of X are bad therefore all of X are bad, before calling "fallacy" I would want to know what X are. If X are murders, I wouldn't have a problem with this. If X were the number of strikes in a baseball game, I still wouldn't argue a fallacy, I would simply say they don't know how baseball works. Likewise, if someone were to argue that a large amount of chemical X is poison, therefore, a minuscule amount of chemical X is poison, I would argue that they don't know how poisons work. I see this more as a problem of specialized knowledge than a fallacy.

Having said all this, anyone can argue a fallacy if the conclusion doesn't follow (a basic non sequitur ). Depending on X, it might not follow that all amounts of X are bad only if some are. Fallacies are sometimes less helpful than pointing out specific errors in understanding. I think this one of those cases. For example, simply telling someone their conclusion "doesn't follow" is not very helpful. WHY doesn't it follow? This is where specific fallacies come in where there is an error in the form of the argument. In this case, the error is domain/context dependent.

I hope all this is clear and makes sense. I struggled on this one for a while and am certainly open to other points of view.