Exactly. You willfully make a choice as to which of these actions is the "best" whilst admitting that you are probably not in full posession of the facts.
Seems a little precarious to me.
There is a difference between thinking and knowing.If one thinks something, he is in effect setting his thoughts and beliefs up in prediction that they might be disproved or corrected in some way. If one knows something, he believes with precise judgment that his thoughts and beliefs are correct and cannot be disproved or corrected. Knowing something does not require the use of the senses, it requires logic, thinking, assembling the known facts that have either been obtained or formulated by the mind, and putting them together in the right position to complete the big picture.
Facts are what we make them to be, one can believe anything, he is not shackled to a predefined logic engine like an animal, running about making decisions based on one particular input of information. If one knows that the world he sees and feels is real, then it is, in all actuality, because he knows this and does not simply think it. If one thinks it, he can only be proven right or wrong, but only proven by the one who knows.
To answer the main question, whether or not one can justify their actions and/or decisions if they cannot be sure the factors are actual, if one makes a decision based on an assumption and not a belief, if one thinks and does not know, then he cannot justify his actions because he is either one of three things: a child, an animal, or an idiot. If one knows, however, bases his decision on his own known facts that he is sure of, that is all the justification he needs, as his decision, no matter how poor or extreme, was correct, because it was based on facts, known facts, not thought facts.