The only unchangeable certainty is that nothing is certain or unchangeable

The new guidance will benefit many thousands of patients, especially those with life-threatening conditions and will provide greater certainty about the provision of important new treatments.

When I was young I was sure of everything; in a few years, having been mistaken a thousand times, I was not half so sure of most things as I was before; at present, I am hardly sure of anything but what God has revealed to me.

If we insist on being as sure as is conceivable... we must be content to creep along the ground, and can never soar.

There is no such thing as absolute certainty, but there is assurance sufficient for the purposes of human life.

There is no indication that there was any certainty about when this will happen. And to me it sounds like a bunch of bureaucratic mumbo jumbo about the process that they have in that country [Japan}.