I'm counting on you to explain everything calmly.
Indeed, it is only by experience that we can know that any definite process of counting will give the true cardinal number of some class of entities.
It is perfectly possible to imagine a universe in which any act of counting by a being in it annihilated some members of the class counted during the time and only during the time of its continuance.
The Crusades had sprung from the policy of a theocratic government counting on the motive of otherworldliness; they had helped in their course to overthrow that motive, and with it the government which it had made possible.