certainty is limiting and expensive

Descartes sought something very firm, very true, unassailable, certain.  He wondered about illusion but he knew that he had thoughts.  Someone who has thoughts must exist so:

"I think, therefore I am"

But for most people, illusions and dreams are not that big an issue.  Over time, they begin to wonder about significance, not wispy, foggy thoughts.  Sometimes, they ask,"What does it all mean?"  Or, "Is this all there is?"  The great religions offer the advice to seek broader meaning beyond the self.  Service to others lifts one's horizons beyond the self, beyond personal boundaries.  

The Boy Scout is enjoined to do a good deed every day.  The classic example is assisting an old lady across the street.  The classic misstep is assisting an old lady across a street that she doesn't want to cross.  Service to others is not service if it doesn't actually assist.  It isn't always easy to find something that you can really do that will be a genuine aid.  OK, then, has a good chance of being a genuine aid, since you can't always be sure that something will be a help.

See what I mean?  If we demand certainty before taking any steps, we can't do much.  Our knowledge is always iffy, always incomplete, murky, uncertain.  It is good to be philosophical at times, to ponder and wonder (which should be rhymes but they aren't).  But there is also such a thing as "analysis paralysis", too much thinking, too little daring.  Trying to be of service, with awareness, taking what is probably a helpful action and then accepting that it was a help, or that you made an honest mistake and it wasn't - that is often approximately how you can actually help.