does not require words. A speaker may conceive the meaning of what he says without words, and a listener can do so without anyone addressing him at all. How, then, can it be said that simple concepts can be conceived only through definitions?

(Ninth: A person conceives existing things either through his external senses, as with taste, colour, smell, and the bodies possessing these attributes, or through his internal senses, as with hunger, love, hatred, joy, sorrow, pleasure, pain, volition, aversion, and the like. None of these requires a definition.

(Tenth: They say that an objector may challenge a definition by presenting counterexamples to its applicability or exclusiveness, or by opposing it with another definition. If someone hearing a definition can invalidate it, sometimes through counterexamples and sometimes through a competing definition—and it is well known that neither is possible without first conceiving what is being defined—then it follows that what is being defined can be conceived without the definition. This is precisely what we seek to establish.

(Eleventh: They acknowledge that some conceptions are self-evident and require no definition. It may then be said that whether knowledge is self-evident or inferential is a relative matter. What requires inference for one person may be self-evident to another because he has acquired it through such means as direct observation, mass transmission, or corroborating indications. People’s powers of apprehension vary beyond any fixed measure. Thus, what is self-evident to one person but not another may likewise become self-evident to the latter through means like those available to the former, without any need for a definition.