In the language of everyday life it very often happens that the same word signifies in two different waysâ âand therefore belongs to two different symbolsâ âor that two words, which signify in different ways, are apparently applied in the same way in the proposition.
Thus the word âisâ appears as the copula, as the sign of equality, and as the expression of existence; âto existâ as an intransitive verb like âto goâ; âidenticalâ as an adjective; we speak of something but also of the fact of something happening.
(In the proposition âGreen is greenââ âwhere the first word is a proper name and the last an adjectiveâ âthese words have not merely different meanings but they are different symbols .)