 Another aspect that different readings of (ES) can vary across concerns the nature of the equivalence that its instances assert. On one view, the right-hand side and the left-hand side of such instances are synonymous or analytically equivalent. Thus, for sententialists who endorse this level of equivalence, (1) asserts that, “‘Brutus killed Caesar’ is true” means just what ‘Brutus killed Caesar’ means; while for propositionalists who endorse analytic equivalence, (2) asserts that ‘the proposition that Brutus killed Caesar is true’ means the same as ‘Brutus killed Caesar’. A second view is that the right-hand and left-hand sides of claims such as (1) and (2) are not synonymous but are nonetheless necessarily equivalent; this view maintains that the two sides of each equivalence stand or fall together in every possible world, despite having different meanings. And a third possible view is that claims such as (1) and (2) assert only a material equivalence; this view interprets the ‘if and only if’ in both (1) and (2) as simply the biconditional of classical logic.