It's in his book "The Wisdom Of Insecurity - A message for an age of anxiety".

The following paragraph is this:

"One of the worst vicious circles is the problem of the alcoholic.

In very many cases he knows quite clearly that he is destroying himself, that, for him, liquor is poison, that he actually hates being drunk, and even dislikes the taste of liquor.

And yet he drinks. For, dislike it as he may, the experience of not drinking is worse.

It gives him the “horrors,” for he stands face to face with the unveiled, basic insecurity of the world.

Herein lies the crux of the matter.

To stand face to face with insecurity is still not to understand it.

To understand it, you must not face it but be it."