Logical consequences are the scarecrows of fools and the beacons of wise men.

And although I have seen nothing but black crows in my life, it doesn't mean that there's no such thing as a white crow. Both for a philosopher and for a scientist it can be important not to reject the possibility of finding a white crow. You might almost say that hunting for 'the white crow' is science's principal task.

Eagles commonly fly alone. They are crows daws and starlings that flock together.