The fourth division of judgement is said to be in respect of modality into assertoric, problematic, and apodeictic, the conceptions involved being respectively those of possibility and impossibility, of actuality and non-actuality, and of necessity and contingence.
"Kant's Theory of Knowledge"
Harold Arthur Prichard
The trajectory is composed of equal elements, with an invariable angle between them; it is the curve whose tangents, divided by infinitely small distances, retain the same inclination between each one and the next; the curve, in a word, with a constant angle of contingence.
"The Glow-Worm and Other Beetles"
Jean Henri Fabre