"They are apt to be extremely general.

In fact, I would affirm that the certainty of the truth of a given proposition is directly proportional to its generality." "I suppose that is so," said I.
"Undoubtedly.

Take an instance from your own profession.

Given a million normal human beings under twenty, and you can say with certainty that a majority of them will die before reaching a certain age, that they will die in certain circumstances and of certain diseases.

Then take a single unit from that million, and what can you predict concerning him?
Nothing.