imperious and ruthless [imperious = arrogantly domineering]

impertinent and personal

impinging and inexorable

implacable and destructive

important and formidable

imposed and enforced

impossibilities and absurdities

impressible and plastic

improvement and progress

imprudent and thoughtless

impulse and indignation

inaccessible and audacious

inactive and supine

inadequate and misleading

inapplicable and alien

inarticulate and confused

inborn and native

incensed and alarmed

inchoate and tentative [inchoate = imperfectly formed]

incoherent and inconclusive

incompetence and ignorance

incomplete and erroneous

incongruity and absurdity

inconvenient and troublesome

incorrigible and irrepressible

incredulous and mortified

indefatigable and irresistible

indefinite and vague

independent and democratic

indifference and brevity

indigence and obscurity

indignation and chagrin

indirectly and unconsciously

indispensable and irreplaceable

indistinct and misty

indolence and indifference

indomitable and dogged

indorsed and applauded

indulge and cherish

industrious and vigilant

ineffective and bungling

inert and uncertain

inevitable and assured

inexhaustible and indomitable

inexperienced and timid

infallible and disdainful

inference and suggestion

infinite and eternal

inflexible and unchanging

influence and authority

informed and competent

ingenious and eloquent

ingratitude and cruelty

inharmonious and irregular

injustice and inhumanity

innocence and fidelity

innuendo and suggestion

inopportune and futile

insanely and blindly

inscrutable and perplexing

insecurity and precariousness

insensibly and graciously

insignificant and transitory

insincere and worthless

insipid and silly

insistent and incongruous

insolence and absurdity

inspiring and animating

instant and momentous

instinctive and rational

insulted and thwarted

intangible and indefinable

integral and indestructible

integrity and honor

intelligence and insight

intense and overpowering

intentness and interest

interesting and engrossing

intimate and familiar

intolerant and bumptious [bumptious = loudly assertive; pushy]