inflexibility

[Cf. F. inflexibilité.]
The quality or state of being inflexible, or not capable of being bent or changed; unyielding stiffness; inflexibleness; rigidity; firmness of will or purpose; unbending pertinacity; steadfastness; resoluteness; unchangeableness; obstinacy.

The inflexibility of mechanism.

That grave inflexibility of soul.

The purity and inflexibility of their faith.

noun

The quality or state of being stubbornly inflexible: die-hardism, grimness, implacability, implacableness, incompliance, incompliancy, inexorability, inexorableness, inflexibleness, intransigence, intransigency, obduracy, obdurateness, relentlessness, remorselessness, rigidity, rigidness, stubbornness. See resist/yield.

The noun has 2 meanings:

Meaning #1: a lack of physical flexibility
  Synonym: inflexibleness
  Antonym: flexibility (meaning #1)

Meaning #2: the quality of being rigid and rigorously severe
  Synonym: rigidity
  Antonym: flexibility (meaning #2)