"I am not one of those people whose minds are so limited that they are unable to conceive of more than one kind of substance."

"imaginary numbers are a fine and wonderful resource of the divine intellect, almost an amphibian between being and non-being."

"It is a great evil to be in doubt about the most important things."

"The monad is nothing but a simple substance that enters into composites."

"To be is to be one."