All Knowledge is a question of Certainty.
Nothing can be said to be 100% certain... but those things which are highly certain may be said to be Known.
Things which may be said to be Certain fall into two Categories: That which is Necessary; That which is Proven
That Which is Proven is that which has been reliably experienced; The Reliability of an Experience is determined by its relation to other experiences as well as to that which has been shown to be Necessary and that which has been shown to be Probable. That which is Proven need not be Necessary or Probable: I am Proven (all that cogito bullshit) but certainly not Necessary and not particularly Probable (on the cosmic scale)
That Which is Necessary is that which follows logically from That Which is Proven. That Which is Proven False (Disproven) is Shown to be Not Necessary (Unnecessary)
That Which is Probable is that which follows logically from That Which is Necessary as well as that which has been experienced but not Proven and that which has been reported by reliable external sources. The Reliability of External Sources is determined by the history of past reports which have been Proven, Shown to be Necessary, and Shown to be Probable.
Those things which have not been Proven one way or the other may be talked about in reference to their Probability or Necessity. A thing may be shown to be Not Necessary but Probable and so thought to exist and included in theoretical models provisionally. A thing may be shown to be Necessary even if Not Probable (Improbable) (2 distinct categories?) such a thing may be said to be Known as would a thing Proven. However should a thing called Necessary be Disproven such a thing would be Shown to be Unnecessary and the Knowledge of it to have been mistaken. Ultimately all Knowledge and Certainty flow from Experience and while Necessity and Probability may be used to judge and assess Experience if an Experience or collection of Experiences are determined to be reliable then the Necessity and Probability of an idea must be reassessed in accord with the Experience. The Three categories of Proof Necessity and Probability for a mutually supporting pyramid in support of Certainty and Knowledge.
