"unverifiable assumptions [that] are used as a priori" are called axioms. Could you tell me what the axioms of science are? Regards, Regner Trampedach This is going back a long time, but from my geometry, an axiom was a "self evident truth." An axiom did not have to be proven. eg a straight line is the shortest distance between two points. Whereas that the three internal angles of a triangle totaled 180 degrees had to proven by geometry, and was not an axiom. Your "axioms are ....unverifiable assumptions " is a new one to me.. I would have expected science to stick to the geometry definition period. But in the light of this 1913 revelation to me today, my whole world of faith in scientific honesty is in ruins. From Webster's Revised Unabridged Dictionary (1913) [web1913]: Axiom, n.-- L. axioma, Gr.; that which is thought worthy, that which is assumed, a basis of demonstration, a principle, fr.; to think worthy, fr.; worthy, weighing as much as; cf.; to lead, drive, also to weigh so much: cf F. axiome. See Agent. 1. (Logic and Math.) A self-evident and necessary truth, or a proposition whose truth is so evident as first sight that no reasoning or demonstration can make it plainer; a proposition which it is necessary to take for granted; as, ``The whole is greater than a part;'' ``A thing can not, at the same time, be and not be.'' 2. An established principle in some art or science, which, though not a necessary truth, is universally received; as, the axioms of political economy. This is again dishonest, as it makes what is universally received and accepted as being the truth. Truth is not based upon a vote.. Democracy gone mad. I have to agree with the next line of the above. "These definitions are the root of much Evil in the worlds of philosophy, religion, and political discourse." http://www.phy.duke.edu/~rgb/Philosophy/axioms/axioms/node27.html These first of these two definitions is almost universally taught (generally in Euclidean Geometry, which is the only serious whole-brain math course that nearly all citizens in at least the United States are required to take to graduate from high school and which is therefore not infrequently the only math outside of a few courses in symbolic or predicate logic and maybe a course in algebra that a humanities-loving philosophy major is typically exposed to). A relatively few students may move on and hear the term used in the second, ``wishful'' sense (wishful in that by calling an established principle an ``axiom'' one is generally trying to convince the listener that it is indeed a ``self-evident and necessary truth''). I like that, but this was a long page......I might go back and finish it before I sing its praises. His dishonesty showed in the succeeding paragraph by his attempt to neutralise truth with non-Euclidean geometry, for no other reason than to destroy a true definition and force people to accept lies as assumptions, and hence truth.... WOW! Philip.