i think you meant to say it doesn't yield truth. Logic can work on false premises and still remain logical.
Its that tid bit that can be misleading to the person believing they have constructed a logical code to live by. Even though the conclusions properly follow the premises, they are still dependent on the premises being true.
This is a trap I often catch myself in all sorts of mental pursuits in my profession (accounting,tax financial planning). I may have created a wonderfull, logical and beautiful plan or tax argument only to discover upon review one of my premises is wrong.
Its often called ASS U ME, -makes an ass out of u and me.
The interesting thing is the more I practive the more I find that its impossible to be completely sure of your premises in anything.
Yes, quite so. By way of clarification, logic is a process, not a result, and so one may be perfectly logical, even in proceeding from false premises. One can even validly arrive at a true conclusion with false premises, but it's not guaranteed, and it's unsound logic even if you do.
And there's the rub - how do you know your premises are true, that your underlying axioms are true? Well, you rolls the dice, and you takes your chances, pretty much ;)