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Conditional: E.g. if it is true that p, it is true that q, is claiming no truth.
Conditional/Brandom: for Frege the most important - without it, you can do something only by agreeing or rejecting - with the conditional you can say something: namely that one approves an inference.
Expressive Vernunft Frankfurt 2000
Begründen und Begreifen Frankfurt 2001