On the Fourfold Root of the Principle of Sufficient Reason

§ 4 Importance of the Principle of Sufficient Reason

Its importance is indeed very great, since it may truly be called the basis of all science. For by science we understand a system of notions, i.e. a totality of connected, as opposed to a mere aggregate of disconnected, notions. But what is it that binds together the members of a system, if not the Principle of Sufficient Reason? That which distinguishes every science from a mere aggregate is precisely, that its notions are derived one from another as from their reason. So it was long ago observed by Plato: καὶ γὰρ αἱ δόξαι αἱ ἀληθεῖς οὐ πολλοῦ ἄξιαί εἰσιν, ἕως ἄν τις ἀυτὰς δήσῃ αἰτίας λογισμῷ (etiam opiniones veræ non multi pretii sunt, donec quis illas ratiocinatione a causis ducta liget).13 Nearly every science, moreover, contains notions of causes from which the effects may be deduced, and likewise other notions of the necessity of conclusions from reasons, as will be seen during the course of this inquiry. Aristotle has expressed this as follows: πᾶσα ἐπιστήμη διανοητική, ἢ καὶ μετέχουσά τι διανοίας, περὶ αἰτίας καὶ ἀρχάς ἐστι (omnis intellectualis scientia, sive aliquo modo intellectu participans, circa causas et principia est).14 Now, as it is this very assumption à priori that all things must have their reason, which authorizes us everywhere to search for the why, we may safely call this why the mother of all science.