“The greatness of a life can only be estimated by the multitude of its actions. We should not count the years, it is our actions which constitute our life.”

There are also two kinds of truths: truth of reasoning and truths of fact.

There is nothing without a reason.

The monad, of which we shall speak here, is nothing but a simple substance which enters into compounds; simple, that is to say, without parts.

This is why the ultimate reason of things must lie in a necessary substance, in which the differentiation of the changes only exists eminently as in their source; and this is what we call God.

It is necessary to believe that the mixture of evil has produced the greatest possible good: otherwise the evil would not have been permitted.

Now where there are no parts, there neither extension, nor shape, nor divisibility is possible. And these monads are the true atoms of nature and, in a word, the elements of things.

Every substance is as a world apart, independent of everything else except God.

We live in the best of all possible worlds.

Whence it follows that God is absolutely perfect, since perfection is nothing but magnitude of positive reality, in the strict sense, setting aside the limits or bounds in things which are limited.

The present is big with the future, the future might be read in the past, the distant is expressed in the near.

We should like Nature to go no further; we should like it to be finite, like our mind; but this is to ignore the greatness and majesty of the Author of things.

Natural religion itself, seems to decay very much. Many will have human souls to be material: others make God himself a corporeal being.

Music is a hidden arithmetic exercise of the soul, which does not know that it is counting.

Taking mathematics from the beginning of the world to the time when Newton lived, what he had done was much the better half.

In my judgment an organic machine new to nature never arises, since it always contains an infinity of organs so that it can express, in its own way, the whole universe; indeed, it always contains all past and present times.

Everything that is possible demands to exist.