That Which Is True of Our Ideas of Things Must Be True of the Things Themselves

Accordingly, a large proportion of the erroneous thinking which exists in the world proceeds upon a tacit assumption, that the same order must obtain among the objects in nature which obtains among our ideas of them. That if we always think of two things together, the two things must always exist together. That if one thing makes us think of another as preceding or following it, that other must precede it or follow it in actual fact. And conversely, that when we cannot conceive two things together they cannot exist together and that their combination may, without further evidence, be rejected from the list of possible occurrences.

-John Stuart Mill

Here is an interesting exercise in a priori from the New York Times op-ed page. Because the recently revealed nuclear facility at Qom, Iran makes no sense as a nuclear-bomb-making facility, it must be a part of a diversified bomb-making program. Yes, this is the sort of Jesuitical logic that makes the Times America's leading publication.