illocutionary act; immediate inference; impartiality; incommensurability; incontinence; incorrigible; indexical; indirect proof; individual constant; individual variable; indubitable; ineffable; inference; infinite regress; informal fallacy; informative use of language; ingenium; intentionality; interactionism; intertextuality; intrinsic - extrinsic; intuitionism; irony; irrelevant conclusion; -ism;