There are two consequences in history; an immediate one, which is instantly recognized, and one in the distance, which is not at first perceived. These consequences often contradict each other;. . . look to the end of an accomplished fact, and you will see that it has always produced the contrary of what was expected from it.
It is one of the aims of linguistics to define itself, to recognise what belongs within its domain. In those cases where it relies upon psychology, it will do so indirectly, remaining independent.