When I was eleven or twelve years old, I became for a while fixated on the question whether there could be two 'identical' stones. This is, of course, the question whether the principle of identity of indiscernibles is true and, as I formulated it then, I was bound to fall into confusion about it.
Knowledge has the form of a tree, and since metaphysics is the most fundamental one of the theoretical disciplines, it represents the roots of the tree.
For bundles of universals can be in more than one place at the same time; so a bundle can have more than one instance; so there can be numerically distinct particulars sharing the same universals; so the principle of identity of indiscernibles is false.
There are different interpretations of the problem of universals. I understand it as the problem of giving the truthmakers of propositions to the effect that a certain particular is such and such, e.g. propositions like 'this rose is red'. Others have interpreted it as a problem about the ontological commitments of such propositions or a problem about what those propositions mean.
A truthmaker is an entity in virtue of which the proposition it makes true is true. And it is a necessary condition of being a truthmaker (though not a sufficient one) that a truthmaker necessitates the proposition it makes true.
I do not believe in the bundle theory anyway. The bundle theory postulates universals and I do not believe in them; so I do not believe in the bundle theory.
By arguing that the bundle theory does not entail and is not committed in any way to the principle of identity of indiscernibles, I have thereby defended the bundle theory from a traditional objection to it.
In my view the bundle theorist should say that when a bundle is located somewhere, there is an 'instance' of the bundle there. The instance is entirely constituted by the universals of the bundle. But the bundle and the instance are two distinct entities. Bundles of universals can be multiply located, but their instances cannot, and particulars are instances of a bundle of universals.
The difference between resemblance nominalism and class nominalism is that the former, but not the latter, brings in resemblance to account for the truthmakers of the propositions in question.
The huge majority of philosophers seem to think that including impure properties in the range of the quantifiers of the principle would make the principle trivial. I have argued that it does not.
The problem of how to characterise the properties that would trivialise the principle is one of the hardest problems concerning the principle of identity of indiscernibles and one the problems to which least attention has been paid of.
Leibniz believed in freedom, both divine and human, and he thought that contingency was a necessary condition of freedom. That is, if an agent A acts freely when choosing X, then A's choosing X cannot be necessary. But there are some elements in his philosophy that seem to make contingency impossible.
The parallelism, or denial of any causation between mind and body, derives basically, and fallaciously, from a theory of substances as having complete concepts that include everything that is true of them.
I would say I was a philosophical boy. Thoughts about 'identical stones' are the earliest philosophical thoughts I remember. But when I was a teenager I also thought about the more typical philosophical problems teenagers think about: the existence of god, the objectivity of morality, whether one can know that the external world exists.
At one point I took a copy of Berkeley's Principles from my father's library. That was the first philosophy book I read. I found it fascinating and wanted to read more philosophy.
I decided to do philosophy at university, with a view to becoming a professional philosopher. Being a rather unstable character, at some points I had doubts about becoming a professional philosopher, but the example of two of my teachers, Ezequiel de Olaso and Juan Rodriguez Larreta, made me confirm my original decision.
Those who take knowledge to be a whole zoo of sub-disciplines will react to my giving metaphysics a privileged position in that zoo or to my thinking of knowledge as a tree, with more and less fundamental parts.
Those who think that metaphysics is just misunderstood grammar will react to my giving metaphysics some place or another in the system of knowledge.
Metaphysics is the study of the most general nature and basic structure of reality, and therefore the concepts of metaphysics, concepts like time, space, identity, resemblance, substance, property, fact, event, composition, possibility, etc., are the most fundamental concepts. Thus metaphysics is the most fundamental theoretical discipline.
The role of metaphysics in relation to other disciplines, whether philosophical or not and including the natural sciences, is thus a foundational role. Lack of clarity in the concepts of metaphysics implies lack of clarity in other disciplines - both theoretical and practical disciplines - employing those concepts or employing concepts that depend on those of metaphysics.
Although I felt I was quite good at criticising a philosophical position, I was not very good at defending and making a case for a philosophical position.
I think there is a metaphysical problem of the relation between mind and body. Thinking that there is no metaphysical dimension to the problem is an error.
Imperfect communities show that being a maximal resemblance class is not sufficient for being a property.
