Not doubt, certainty is what drives one insane.

Indeed, what forces us at all to suppose that there is an essential opposition of 'true' and 'false'? Is it not sufficient to assume degrees of apparentness and, as it were, lighter and darker shadows and shades of appearance- different 'values', to use the language of painters?

Shackled heart, free spirit.--Whoever binds his heart tightly and imprisons it may indulge his spirit in many liberties: I have already said that once. But no one believes me unless he already knows.

The Gay Science, section 108

If you buy the why, the how is infinitely bearable

God is a gross answer, an indelicacy against us thinkers- at bottom merely a gross prohibition for us: you shall not think!

The greatest giver of alms is cowardice.