Gottfried Wilhelm Leibniz

QUOTES

"...monads or simple substances are the only true substances and that material things are only phenomena, though well founded and well connected..."Enter
"...everything in nature happens mechanically and at the same time metaphysically but that the source of mechanics is metaphysics..."
"Our reasonings are based on two great principles, that of contradiction… [and] that of sufficient reason."
“it is not true that two substances can resemble each other completely and differ only in number [solo numero].”
"Nothing takes place suddenly, and it is one of my great and best confirmed maxims that nature never makes leaps."
"I consider the notion of substance to be one of the keys to the true philosophy"

NOTES

eclectic mix of Aristotle and Christian Platonism
reaction to two sets of modern opponents: on the one hand, Descartes and his followers; on the other hand, Hobbes and Spinoza
God freely chose the best world from an infinite number of possible worlds
a person could be said to act freely when the contrary of that action does not imply a contradiction
The Principle of Sufficient Reason (PSR) in its classic form is simply that nothing is without a reason (nihil est sine ratione) or there is no effect without a cause.
nothing takes place without a sufficient reason means that nothing happens in such a way that it is impossible for someone with enough information to give a reason why it is so and not otherwise
every event must have a cause and that there is a reason why everything is so and not otherwise
everything is composed of or reducible to simple substances
x is a substance if and only if x has a complete individual concept (CIC), that is, a concept that contains within it all predicates of x past, present, and future

The Identity of Indiscernibles

Gottfried Wilhelm Leibniz 1