Q:

Empiricism out the door

I remember having read something like 

No matter how long we debate about the existence of the external world, at the end of the evening we all exit the room through the door

Or something like that.. I think it is a quote from one of the early British empiricists, or related to one of them in some way. Can anyone identify it and provide the exact quotation as well as the related circumstances?

A:

David Hume wrote this line in his character Cleanthes's voice, in Part One of Dialogues Concerning Natural Religion:

Whether your scepticism be as absolute and sincere as you pretend, we shall learn by and by, when the company breaks up: we shall then see, whether you go out at the door or the window; and whether you really doubt if your body has gravity, or can be injured by its fall; according to popular opinion, derived from our fallacious senses, and more fallacious experience.

The context is that Philo has just responded to Cleanthes's endorsement of teaching children piety. Philo's opening response involves expressing the importance of a general skepticism, of caution about certainty and thinking that we understand what we cannot actually explain. Cleanthes is then challenging Philo in this passage on how sincere his skepticism is.

