Conceptual necessity is a property of the certainty with which a state of affairs, as presented by a certain description, occurs: it occurs by conceptual necessity if and only if it occurs just by virtue of the meaning of the description. If someone is a bachelor, for instance, then he is bound to be unmarried by conceptual necessity, because the meaning of the word "bachelor" determines that he is.
Alternatively, there is metaphysical necessity, which is a certainty determined, not by the meaning of a description, but instead by facts in the world described.
Famous quotes containing the words conceptual and/or necessity:
“Analyze theory-building how we will, we all must start in the middle. Our conceptual firsts are middle-sized, middle-distanced objects, and our introduction to them and to everything comes midway in the cultural evolution of the race.”
—Willard Van Orman Quine (b. 1908)
“This, indeed, has always been the fate of the few that have professed scepticism, that, when they have done what they can to discredit their senses, they find themselves, after all, under a necessity of trusting to them. Mr. Hume has been so candid as to acknowledge this; and it is no less true of those who have shewn the same candour; for I never heard that any sceptic runs his head against a post, or stepped into a kennel, because he did not believe his eyes.”
—Thomas Reid (1710–1796)