Accident (philosophy) in the context of "Metaphysical necessity"

Process philosophy (also ontology of becoming or processism) is an approach in philosophy that identifies processes, changes, or shifting relationships as the only real experience of everyday living. In opposition to the classical view of change as illusory (as argued by Parmenides) or accidental (as argued by Aristotle), process philosophy posits transient occasions of change or becoming as the only fundamental things of the ordinary everyday real world.

Since the time of Plato and Aristotle, classical ontology has posited ordinary world reality as constituted of enduring substances, to which transient processes are ontologically subordinate, if they are not denied. If Socrates changes, becomes sick, Socrates is still the same (the substance of Socrates being the same), and change (his sickness) only glides over his substance: change is accidental, and devoid of primary reality, whereas the substance is essential.

Essence (Latin: essentia) has various meanings and uses for different thinkers and in different contexts. It is used in philosophy and theology as a designation for the property or set of properties or attributes that make an entity the entity it is or, expressed negatively, without which it would lose its identity. Essence is contrasted with accident, which is a property or attribute the entity has accidentally or contingently, but upon which its identity does not depend.

In linguistics an accidental gap, also known as a gap, paradigm gap, accidental lexical gap, lexical gap, lacuna, or hole in the pattern, is a potential word, word sense, morpheme, or other form that does not exist in some language despite being theoretically permissible by the grammatical rules of that language. For example, a word pronounced /zeɪ̯k/ is theoretically possible in English, as it would obey English phonological rules, but does not currently exist. Its absence is therefore an accidental gap, in the ontologic sense of the word accidental (that is, circumstantial rather than essential).

Accidental gaps differ from systematic gaps, those words or other forms which do not exist in a language due to the boundaries set by phonological, morphological, and other rules of that specific language. In English, a word pronounced /pfnk/ does not and cannot exist because it has no vowels and therefore does not obey the word-formation rules of English. This is a systematic, rather than accidental, gap.