Lacking worth or importance:
— His work seems trivial and inconsequential.

synonym: inconsequent.

Roget 732: unsuccessful, successless^†; failing, tripping etc. v.; at fault; unfortunate etc. 735.    abortive, addle, stillborn; fruitless, bootless; ineffectual, ineffective, inconsequential, trifling, nugatory; inefficient etc. (impotent) 158; insufficient etc. 640; unavailing etc. (useless) 645; of no effect.    aground, grounded, swamped, stranded, cast away, wrecked, foundered, capsized, shipwrecked, nonsuited^†; foiled; defeated etc. 731; struck down, borne down, broken down; downtrodden; overborne, overwhelmed; all up with; ploughed, plowed, plucked.    lost, undone, ruined, broken; bankrupt etc. (not paying) 808; played out; done up, done for; dead beat, ruined root and branch, flambe^†, knocked on the head; destroyed etc. 162.    frustrated, crossed, unhinged, disconcerted dashed; thrown off one's balance, thrown on one's back, thrown on one's beam ends^†; unhorsed, in a sorry plight; hard hit.    stultified, befooled^†, dished, hoist on one's own petard; victimized, sacrificed.    wide of the mark etc. (error) 495; out of one's reckoning etc. (inexpectation) 508^†; left in the lurch; thrown away etc. (wasted) 638; unattained; uncompleted etc. 730.    ... show more

Roget 175a: uninfluential^†, ineffective; inconsequential, nugatory; unconducing, unconducive, unconducting to^†; powerless etc. 158; irrelevant etc. 10.   

Roget 477: intuitive, instinctive, impulsive; independent of reason, anterior to reason; gratuitous, hazarded; unconnected.    unreasonable, illogical, false, unsound, invalid; unwarranted, not following; inconsequent, inconsequential; inconsistent; absonous^†, absonant^†; unscientific; untenable, inconclusive, incorrect; fallacious, fallible; groundless, unproved; non sequitur [Lat.], it does not follow.    deceptive, sophistical, jesuitical; illusive, illusory; specious, hollow, plausible, ad captandum [Lat.], evasive; irrelevant etc. 10.    weak, feeble, poor, flimsy, loose, vague.    irrational; nonsensical etc. (absurd) 497.    foolish etc. (imbecile) 499; frivolous, pettifogging, quibbling; finespun^†, overrefined^†.    at the end of one's tether, au bout de son latin.    ... show more

Not following logically as a consequence.