stubbornly unyielding. She was a tenacious woman, one who would even hold fast a thing which she no longer valued, simply because it belonged to her.Morris, Clara
Regarding the nature of living beings in this world, reason must assume as a necessary principle that no organ, no faculty, nothing superfluous, or disproportionate to its use, hence nothing purposeless, is to be met with.
Reason must assume as necessary that everything in a living organism has a proportionate purpose
Immanuel Kant (Critique of Pure Reason [1781], B425)