Of Set Theory and Nested Hierarchies

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Carl Linnaeus- 1707- 1778- Nested Hierarchy Classification
Georg Cantor- 1845-1918- Set Theory

Strange, Linnaeus developed his nested hierarchy classification without Cantor's set theory. Geez it looks like I am correct again- ie we don't need set theory to discuss nested hierarchies.

And not only that what is in the nested hierarchy is very important.

Great, Jon F chimes in:

Of course we don’t need set theory to discuss nested hierarchies, but it is applicable and useful.

Obvioulsy it isn't of any use nor is it applicable. Linnaeus didn't need it.