*Salva veritate*

The literal translation of the Latin "* salva veritate*" is "with (or by) unharmed truth", using ablative of manner: "

*salva*" meaning "rescue," "salvation," or "welfare," and "

*veritate*" meaning "reality" or "truth". Thus,

*Salva veritate*(or

**intersubstitutivity**) is the logical condition by which two expressions may be interchanged without altering the truth-value of statements in which the expressions occur. Substitution

*salva veritate*of co-extensional terms can fail in opaque contexts.

^{[1]}

## LeibnizEdit

The phrase occurs in two fragments from Gottfried Leibniz's *General Science. Characteristics*:

- In Chapter 19, Definition 1, Leibniz writes: "Two terms are the same (
*eadem*) if one can be substituted for the other*without altering the truth of any statement*(*salva veritate*)." - In Chapter 20, Definition 1, Leibniz writes: "Terms which can be substituted for one another wherever we please
*without altering the truth of any statement*(*salva veritate*), are the same (*eadem*) or coincident (*coincidentia*). For example, 'triangle' and 'trilateral', for in every proposition demonstrated by Euclid concerning 'triangle', 'trilateral' can be substituted*without loss of truth*(*salva veritate*)."

## QuineEdit

W.V.O. Quine takes substitutivity *salva veritate* to be the same as the "indiscernibility of identicals". Given a true statement, one of its two terms may be substituted for the other in any true statement and the result will be true.^{[2]} He continues to show that depending on context, the statement may change in value. In fact, the whole quantified modal logic of necessity is dependent on context and empty otherwise; for it collapses if essence is withdrawn.^{[3]}

For example, the statements:

(1) | Giorgione = Barbarelli, |

(2) | Giorgione was so-called because of his size |

are true; however, replacement of the name 'Giorgione' by the name 'Barbarelli' turns (2) into the falsehood:

Barbarelli was so-called because of his size.^{[4]} |

Quine's example here refers to Giorgio Barbarelli's sobriquet "Giorgione", an Italian name roughly glossed as "Big George."

## See alsoEdit

## ReferencesEdit

## BibliographyEdit

- Clarence Irving Lewis,
*A Survey of Symbolic Logic*, Appendix, Dover.