Indexing

“In this world ‘complete sameness’ between any two of anything has not yet been demonstrated, for in some respects objects and happenings differ from each other. And the closer to nature we are able to get, the more apparent does this structural fact become.  When the fact of difference has been understood, we should be ready for another — that each item of our acquaintance, each object and happening will appear unique, differing in some details from every other one.” —Lee, Language Habits in Human Affairs, pp. 88, 89

“When you studied algebra you learned to deal with such symbols as x₁ x₂ and the like. The numbers were called subscripts, meaning that they were written under the x. These subscripts are indexes, or index numbers. They are not merely something thought up by some mathematician in a fit of whimsy. They are very useful to the mathematician whenever he wishes to remind you, and himself, that x is a variable term — that is to say, x can be used to represent any number whatever. Thus, at one time it may be used to represent 9, or at another time 118, etc. In other words, x₁ is not x₂. Now, after all, x is like any ordinary word. The word house, for example, is a variable term. It can be used to refer to my house, or to your house, or to any one of all the possible buildings one might want to talk about. And house₁, is not house₂....” —Ibid., pp. 211, 212