Adjective
Not having will or the power of choice.
Not under the influence or control of the will; not voluntary; as, the involuntary movements of the body; involuntary muscle fibers.
Not proceeding from choice; done unwillingly; reluctant; compulsory; as, involuntary submission.
Source: Webster's dictionaryAll beginnings are involuntary. Fernando Pessoa
The organizations of men, like men themselves, seem subject to deafness, nearsightedness, lameness, and involuntary cruelty. We seem tragically unable to help one another, to understand one another. John Cheever
Belief is involuntary; nothing involuntary is meritorious or reprehensible. A man ought not to be considered worse or better for his belief. Percy Bysshe Shelley
Any emotion, if it is sincere, is involuntary. Mark Twain
Concupiscence and force are the source of all our actions; concupiscence causes voluntary actions, force involuntary ones. Blaise Pascal
Involuntary love is worthless. Sicilian Proverb