The rest of the quote is:
"Most great civilized countries have an income tax and an inheritance tax. In my judgment both should be part of our system of federal taxation." Such taxation be aimed merely at the inheritance or transmission in their entirety of those fortunes swollen beyond all healthy limits."
While this seems noble, the problem is the one of "healthy limits". Nobody likes the indolent rich kids like Paris Hilton and her ilk, but do you really think that she's not going to be as odious and wealthy as she is now with our without a tax? As the WSJ pointed out, billionaires have no qualms with inheritance tax b/c they have vehicles available to shelter their income from government attempts to take it.
Inheritance tax hurts the middle class far more than it hurts the uber-wealthy.
I don't understand the logic that we should tax the rich more than the poor. What is the logic? "They can afford it" isn't an arguement. It's boilerplate. Rich people do not use more government services, rather, they use less. They have private health insurance, use private means of transportation and are less likely to use public schools or require the assistance of police officers. Since they are not using more than their share of government services, why should they be taxed more?