Haecceity

He [Ignatius of Loyola] ſaith not this of ſome one Church, but of all; nor yet as of an accident proper to thoſe times of the Churches minority; but as of the Notes of every Churches Individuation or Hæcceity as they ſpeak. The Unity of the Church is characteriſed by One Altar, and One Biſhop with the Presbytery and Deacons.

HÆCCEITY [with Chymiſis] the ſame ſpecifick Eſſence or active Principle, by which a Medicine operates.

But then, precisely the same distinction is applicable to the Hæcceity itself. For it, too, has its notes of similarity with other Hæcceities, as well as its distinctive notes which add something conceptually distinct from the common Hæcceity.

The haecceitist's claim that there exist unexemplified haecceities of disjoint objects is an extremely controversial one. Indeed, many of those who accept an ontology which includes properties vehemently deny the existence of even exemplified haecceities.

What is there in the nature of individual substance which accounts for its unity and activity? As has been argued, [Gottfried Wilhelm] Leibniz did not regard haecceity as able to play this role, but frequently mentioned substantial form as a principle both of unity and activity. This makes it impossible to identify substantial form with haecceity. The strongest remaining possibility seems to be a composition of substantial form and haecceity within the nature of substance.

Since haec is the Latin term for "this," Scotus and his disciples came to refer to this positive additive that individuates an individual's nature or distinctive qualities as that individual's unique or proper "haecceity" (haecceitas). Haecceity or "thisness" has a twofold function: (1) it makes each individual unique and incapable of duplication, even by an omnipotent God; and (2) it differentiates it radically and ultimately from each and every other individual, whether it be of the same or a specially different type.

The late-twentieth-century philosopher Roderick Chisholm, in his Person and Object, suggested such a view: that each of us has an inner self-nature, a "haecceity," which is available to introspective experience. This suggestion (which Chisholm later appeared to drop) had the appeal of having it both ways, preserving individuality (everyone's haecceity is different from everyone else's) while insisting on changelessness.

Being asked to present our work in terms of 'technology' seems to somehow imply it as haecceity – as a graspable essence or entity, a 'this-ness'.

[Gilles] Deleuze and [Félix] Guattari often refer to the Individuals composed from elements as haecceities. Haecceities can be characterized by linguistic phrases involving one or more of the following: an indefinite article, a proper name, or an infinitive verb, for example, "the heat of the day" ("What heat!") as opposed to an exact temperature; "a long day" ("What a long day!") as opposed to the day as a set number of hours; […] Depending on the relations of speed and slowness between the unformed elements that make them up, these haecceities have specific "affects," that is, capacities to affect or be affected by other haecceities.

Following Charles Peirce, I argued that it is the particular haecceity (the thisness), the come-up-againstness, presented by the natural world provides human beings with a particular physical environment within which actions can be fitted to circumstances in certain ways in order to attempt to bring about certain desired results. Therein lies the most fundamental basis for will, choice, and rationality.