[...] another powerful tendency which makes for a formal elaboration that does not strictly correspond to clear-cut conceptual differences [...] is the tendency to construct schemes of classification into which all the concepts of language must be fitted.
- Sapir (1921), a pag.98

It is because our conceptual scheme is a sliding scale rather than a philosophical analysis of experience that we cannot say in advance just where to put a given concept. We must dispense [...] with a well-ordered classification of categories.
- Sapir (1921), a pag.107

A part of speech outside of the limitations of syntactic form is but a will o' the wisp. [...] no logical scheme of the parts of speech -their number, nature, and necessary confines- is of the slightest interest [...] Each language has its own scheme. Everything depends on the formal demarcations which it recognizes.
- Sapir (1921), a pag.119

Isolating, agglutinative, fusional, and symbolic is a preferable scheme, but still skirts the external. We shall do best [...] to hold to 'inflective' as a valuable suggestion for a broader and more consistently developed scheme, as a hint for a classification based on the nature of the concepts expressed by the language.
- Sapir (1921), a pag.136

The other two classifications, the first based on degree of synthesis, the second on degree of fusion, may be retained as intercrossing schemes that give us the opportunity to subdivide our main conceptual types.
- Sapir (1921), a pag.136