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.

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.

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.

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.

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 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.