If philosophy is to become practical, it must make room for individuals. The traditional way in which we approach ontology fails on this standard. The job of ontology is to understand the nature of being, what it means to exist. Traditional ontology understands being by tracing our conceptual representations of beings in terms of their essential characteristics. But this approach will never understand individual beings. We can come up with an infinite number of concepts in our attempts to characterize the nature of an individual but there will always be something that escapes that analysis.
Consider, for instance, a particular chair. It is walnut in color, made of wood, with a hard, flat surface 1.5 ft. square, resting on legs which are about knee high, a rigid back, etc. For practical purposes, this description is accurate and useful. Although these characteristics are shared by a wide variety of chairs and thus don’t characterize this chair as an individual, that usually doesn’t matter. Any number of chairs fitting this description will do if you want to sit down. However, such an attempt to describe a chair by using general concepts will always reach an endpoint that stops well short off characterizing the individuality of a chair.
Thus, while such an approach to ontology may be fine for generic objects, when individuality matters, as it does for art works for example, it’s clearly inadequate, and it’s a disaster when thinking of persons in this way. A woman may be a spouse, a mother, a doctor, an amateur pianist, a fashionista, a dreadful cook, 5’ 5’’ tall, and much more. But no such list will tell us why she is worthy of love or friendship; relationships of love or friendship based on such a list would quickly collapse or become purely instrumental.
The larger philosophical point is that if our methods of doing ontology are in principle incapable of comprehending the being of an object, they are inadequate. Types of things exist but so do individuals and at least some of the time it is crucial that we see them as individuals.
But viewing individuality as central to the being of entities comes at a cost. If the identity of an object is to be, in part, a product of what makes it a unique individual, that identity will be unstable. Highly contingent, unique characteristics are continuously in flux. This is why many relationships go bad—that mysterious connection that binds people to each other can disappear in an instant.
Even the identity of ordinary objects like chairs can be unstable. Chairs are what they are because of certain relations that are only relatively fixed. If chairs were used differently or were used by beings unlike humans, even their general characteristics would change as new chairs were constructed to meet new demands. There is no eternal essence of a chair. This holds true even for biological entities. No doubt, apples have certain relatively stable characteristics. But if apples were used differently or grown differently, if the relations that constitute them change, their features would change as well. The point is that the evolution of the apple is unpredictable under different selection pressures. The “evolution” of a chair is no less contingent.
The kind of thing we are matters—human, male or female, 18 yrs. old or 50 yrs. old—but we don’t live life as kinds of things only. We live as unique individuals, and we encounter and interact with unique individuals. Until philosophy discovers an ontology that can fully accommodate individuals, it will remain an abstract, academic discipline interested in broad generalizations rather than ways of living, which are irreducibly particular.