logic

travel

is like whiskey in that it loses its beneficial effect when taken in too large quantities.

Logic, like whiskey, loses its beneficial effect when taken in too large quantities.

is like whiskey; it loses its beneficial effect when taken in too large quantities.

 comes from some deep urge to see the world, like the urge that brings up a worm in an Irish bog to see the moon when it is full.

I think that travel comes from some deep urge to see the world, like the urge that brings up a worm in an Irish bog to see the moon when it is full.