illusive touch

illustrative anecdote

illustrious era

imaginative warmth

imbittered controversy

immaterial connection

immature dissent

immeasurable scorn

immediate abjuration [abjuration = renounce under oath]

immemorial bulwark

immense complacency

imminent perplexities

immitigable contempt

immoderate grief

immortal creation

immovably silent

immutable law

impaired prestige

impalpable nothingness

impartial justice

impassable serenity

impassioned impulse

impatient yearning

impeccable felicity

impecunious exile

impelling movement

impending fate

impenetrable calmness

imperative necessity

imperceptible deviation

imperfect equipment

imperial authority

imperious mind [imperious = arrogantly domineering or overbearing]

imperishable renown

impersonal compliment

impertinent drollery

imperturbable gravity

impetuous zeal

impious defiance

impish humor

implacable resentment

implicit faith

implied concealment

implored pardon

imponderable air

important epoch

importunate questions [importunate = insistent request]

imposing mien
         [mien = manner revealing a state of mind; appearance or aspect]

impossible contingency

impotent desperation

impoverished age

impracticable obstinacy

impregnable fortress

impressionistic stroke

imprisoning limitations

improbable conjecture

impromptu utterance

improvising powers

imprudent indebtedness

impudent knowingness

impulsive gratitude

inaccessible dignity

inadequate appreciation

inadmissible expression

inadvertent remark

inalienable right

inanimate existence

inapposite blandness [inapposite = inappropriate or misapplied nature]

inaptly designated

inarticulate lispings

inaugural discourse

inborn refinement

inbred taste

incalculable mischief

incarnate hate

incendiary opinions

incessant volume

incidental duty

incipient fancy

incisive critic

incoherent loquacity [loquacity = very talkative]

incommunicable gift

incomparable excellence

incompletely apprehended

inconceivable absurdity

incongruous contrast