Necessity   
var.
Necessary

Necessity

Commens
Digital Companion to C. S. Peirce
Necessity
var.
Necessary
1905 | Issues of Pragmaticism | CP 5.454

when knowledge is indeterminate among alternatives, either there is one state of things which alone accords with them all, when this is in the Mode of Necessity, or there is more than one state of things that no knowledge excludes, when each of these is in the Mode of Possibility.

1905 [c.] | The Branches of Geometry; Existential Graphs [R] | MS [R] 96

Necessity […] is that mode of being which is not subject to the principle of excluded middle, since it may neither be that A is necessarily B, nor that A is necessarily not B. [—] How can the principle of excluded middle fail to apply? By the function of determination being given over to the person addressed.

1908 | The Bed-Rock Beneath Pragmaticism | MS [R] 300:39-40

the Necessary […] is that which tends to govern both Thought and real Fact, even should it never become absolute in either sway.