Personalism in the sense of a distinct philosophy or worldview focusing on the full, accumulated import of the concept of the person, however, emerged only in the context of the broad critical reaction against what can be called the various impersonalistic philosophies which came to dominate the Enlightenment and Romanticism in the form of rationalistic and romantic forms of pantheism and idealism, from Spinoza to Hegel. Key figures in this reaction were Friedrich Heinrich Jacobi (1743–1819), the initiator of the so-called Pantheismusstreit in the 1780s, and F. W. J. Schelling (1775–1854), who in his later work rejected the impersonalist positions of his early idealist systems. (SEP entry "Personalism")In particular following I.H. Fichte was Hermann Lotze (1817-1881) who emphasized the ancient Greek distinction between persons and things within a personalistic idealism. "Persons" were said to be centers of consciousness, properly "subjects" so-called, which can initiate causes and change by their own intentional volition (among other requirements, many outlined in Schelling's Outline nature book), where volition is understood as agency. In Europe this was picked up later on in the metaphysics of the French philosopher Emmanuel Mounier (1905-1950) in his book Personalism. German personalism, by the time of the twentieth-century, had largely been adopted only by the Catholic church but not so much by other philosophers (with the exception of Max Scheler).
While reading this, I had three thoughts that I'd like to type out very, very quickly.
1. Arne Naess, the Norwegian ecophilosopher, proposed we ought to consider mountains "persons," not because they "think" in any regular sense of the term or possess consciousness as in panpsychism (which would be ridiculous), but because of the intrinsic dignity of the mountain afforded by the agency it possesses - its power to affect change. Today, corporations have been long considered "persons." But if a corporation is a "person," then why isn't a mountain? There is a distinction of course between legal and moral rights, yet ontologically legal rights rely upon moral rights - for the value those laws and considerations possess can only be established by the reality and natures of the subjects those laws are said to govern. Thus, according to personalistic criterion, whose lineage goes back to the German idealists and the American personalists who followed from them (from Lotze to Bowne), and the European personalists who followed from the German idealists (in particular Mounier, perhaps Scheler), certain "things" are now being granted rights as persons due to new ontological perspectives which owe their viewpoints to the personalists of the 19th and 20th centuries - for example, recently rivers have been granted the same rights as human beings, due to environmental concerns. See HERE.
2. The danger of miscategorizing all of nature as "objects" or "things" is worse now than its ever been, and this danger is much worse than miscategorizing all of nature as "persons" by way of contrast. Object-oriented ontologies may grant agency to things, fine; but nevertheless objects are things without personal rights, according to their view. Many object ontologies deny consciousness or personhood to even the most basic of "things" for fear that consciousness or personhood is an "anthropocentric" trapping. While I agree we ought to, in the name of an ecological approach, not make our choices according to anthropocentric and heirarchical orderings of value, I do not agree personhood is an improper attribution to non-human animals, for instance; or to rivers and mountains given proper metaphysical consideration. "Objects" - as a category - is, frankly, a depersonalizing categorization from the start. And when one starts with a category mistake, then one's following system is completely flawed from the start for it is flawed in its very foundations. "Agents" would at the very least be a better start, if "persons" is too "humanistic" (which, in cases of helping others less fortunate, the weak, the sick, the dying, then a humanistic-oriented form of personalism is indeed called for. In cases where the weak, the sick, the dying or suffering are non-human animals then the more encompassing form of agentialism, personalism, is called for.
3. If onto-sympathy and empathy are key in understanding persons (persons, not things) as well as their agency, I am wondering about the following when it comes to the connection between persons, each its own center of value deserving dignity, value, and response as a person. The question is. if the real is always concrete and individual, yet through empathy we are able to universalize each individual so that each is its own center of value within a community of fellow centers of value (each is its own "I" so to speak), that it is nevertheless possible to lose a sense of community among the particulars we are universalizing. So in other words, does someone like Max Stirner, for example, make the same mistake as the object ontologists in having each I universalize into its own Absolute such that any chance for empathic community is lost due to that particular I being so absolutely private and distinct from all others that it is always collapsing back into its own universality, thus eliminating the very possibility of any real community or connection, any real contact or feeling, or any communication between each 'I'? Or, on the other hand, is it the case that for Stirner, universality is commens, and in that very collapse there is an inner form of empathy that is the same as the outer extension of touch, feeling, prehension, or whatever modes of interaction allow communication between particulars? This would mean that any "vicarious" form of causation (connection) between them would not be required. No "magic" needed.
Thinking about Stirner and personalism leaves me torn. There seems to be two very different and distinct dimensions at work when one considers Stirner and personalism. Stirner's "ownness" means each One is a Unique One, each particular itself Absolute. This uplifts each individual self, or subject, or person, or agent, to the infinite degree of value it ought to have in being One. Yet, personalism allows for individuals, selves, subjects, agents, to allow their own current status of value to meet the status of value had by another. This is especially apparent in connections involving suffering, to attempt to feel what others do in lack and in need. (See for example Jean Vanier's Becoming Human - I would also point out the work of Robert Spaemann, Jacques Maritain, or Wojtyla's Person and Act.)
Obviously Stirner's "egoistic" (or better, "individualistic") personalism is very, very different from its speculative theist roots. But whether "individualistic" personalism or personalism proper (idealistic personalism), both are extremely preferably beginning points to ontologies which begin from the category mistake of seeing persons as "objects" from the start.
Any subject or agent is not a "thing" - persons are not "things," persons are not "objects." This is the sort of thinking that leads to murder, torture, and genocide, not only of "human" persons, but of non-human persons such as non-human animals. This is why object-oriented ontologies are not able to complete the ethical projects they propose to begin - especially ethical projects dealing with non-human persons (i.e. animal ethics, but there are issues with how it sees environmental justice).
For object-oriented ontology, it seems that ethics is impossible if only because in its treatment of value something quite necessary for ethics is lost. Namely, the notion of a "to whom" might we attribute such a value. In other words, object oriented ontology is unable to recognize the notion of a "subject of a life" and how non-human beings especially (animals) are not objects or "things" but rather are fellow subjects-of-a-life. This is not to anthropocentrically raise up the non-human to some supposed "higher level" of consciousness and feeling occupied by the human being, but nor is it to categorically drain all beings of subjectivity in fear of subjectalism and render all to the common value level of "objects' either.
To see beings as fellow "subjects-of-a-life" is to accept the notion of "ontological parity" (cf. Justus Buchler's Metaphysics of Natural Complexes) among and between any and all beings not just in terms of reality status - that nothing is more nor less real than anything else - but also in terms of axiological value: each being is equally infinite in its dignity, worth, and value so far as it exists... in whatever way it exists. It is from personalism that we inherit the strongest alternative to the kind of thinking that in fear of anthropocentrism reduces all persons to the level of non-personal objects. And this is why ethics shall forever be impossible for object oriented ontology. It is, afterall, object oriented.