where the Turk sets his foot; but it is the other side of the same
truth to say that it would grow anywhere but where it ought to grow.
And though in this case it was but an accident and a symbol,
it was a very true symbol. We talk of the green banner of the Turk
having been planted on this or that citadel; and certainly it
was so planted with splendid valour and sensational victory.
But this is the green banner that he plants on all his high cities
in the end.

Therefore my immediate impression of the walls and gates was
not contradicted by my consciousness of what came before and
what came after that medieval period. It remained primarily
a thing of walls and gates; a thing which the modern world
does not perhaps understand so well as the medieval world.
There is involved in it all that idea of definition which those who do
not like it are fond of describing as dogma. A wall is like rule;
and the gates are like the exceptions that prove the rule.
The man making it has to decide where his rule will run
and where his exception shall stand. He cannot have a city
that is all gates any more than a house that is all windows;
nor is it possible to have a law that consists entirely of liberties.
The ancient races and religions that contended for this city agreed
with each other in this, when they differed about everything else.
It was true of practically all of them that when they built a city they
built a citadel. That is, whatever strange thing they may have made,
they regarded it as something to be defined and to be defended.

And from this standpoint the holy city was a happy city;
it had no suburbs. That is to say, there are all sorts
of buildings outside the wall; but they are outside the wall.