I hold that the mark of a genuine idea is that its possibility can be proved, either a priori by conceiving its cause or reason, or a posteriori when experience teaches us that it is in fact in nature.
Gottfried LeibnizImaginary numbers are a fine and wonderful refuge of the divine spirit almost an amphibian between being and non-being.
Gottfried LeibnizThere is a world of created beings - living things, animals, entelechies, and souls - in the least part of matter.... Thus there is nothing waste, nothing sterile, nothing dead in the universe; no chaos, no confusions, save in appearance.
Gottfried LeibnizBut it is the knowledge of necessary and eternal truths which distinguishes us from mere animals, and gives us reason and the sciences, raising us to knowledge of ourselves and God. It is this in us which we call the rational soul or mind.
Gottfried LeibnizThere are two famous labyrinths where our reason very often goes astray. One concerns the great question of the free and the necessary, above all in the production and the origin of Evil. The other consists in the discussion of continuity, and of the indivisibles which appear to be the elements thereof, and where the consideration of the infinite must enter in.
Gottfried Leibniz