In a rapture of imagined ecstasy

In a secret and surreptitious way
                 [surreptitious = done by clandestine or stealthy means]

In a spirit of friendliness and conciliation

In a state of mulish reluctance [mulish = stubborn and intractable]

In a state of nervous exacerbation

In a state of virtuous complacency

In a tone of uneasy interrogation

In a transport of ambitious vanity

In a whirlwind of feeling and memory

In accents embarrassed and hesitating

In alliance with steady clearness of intellect

In amazed ejaculation

In an eminent and unique sense

In an eminent degree

In deference to a unanimous sentiment

In extenuation of the past

In high good humor

In his customary sententious fashion
                               [sententious = terse and energetic; pithy]

In its most odious and intolerable shape

In language terse yet familiar

In moments of the most imminent peril

In quite incredible confusion

In seasons of difficulty and trial

In spite of plausible arguments

In terms of imperishable beauty

In the dim procession of years

In the highest conceivable degree

In the local phrase

In the nature of things

In the ordinarily accepted sense

In the realm of conjecture

In the scheme of things

In the tone of one who moralizes

In the twinkling of an eye

In the world of letters

In tones of genuine admiration

Incapable of flashy make-believe

Incited by a lust for gain

Incomparable lucidity and penetrativeness

Inconceivable clumsiness of organization

Indulge a train of gentle recollection

Indulging a sickly and nauseating petulance

Ineffably dreary and unpicturesque

Infected with a feverish dissatisfaction

Infuse a wholesome terror

Inimical to true and determined principle [Inimical = harmful; adverse]

Inimitable grace and felicity [inimitable = defying imitation; matchless]

Injudicious and inelegant ostentation

Innumerable and incessant creations

Inordinate greed and love of wealth

Insatiably greedy of recognition

Insensibility to moral perspective and proportion

Insolent and riotous excess

Inspired by a vague malevolence

Inspirited by approval and applause

Instances might be multiplied indefinitely

Instantly alive to the slightest breach of decorum

Insufferable violence to the feelings

Intense and stubborn dogmatism

Intense sensitiveness to injustice