The Principle of Sufficient Reason Causality is a metaphysical assumption. Leucippus: Naught happens for nothing, but everything from a ground and of necessity. Leibniz: nothing happens without a reason. By Keith.Gillette|2016-06-13T08:43:00-04:002016-06-13|IdeaLog|0 Comments Care to share? FacebookTwitterRedditLinkedInWhatsAppTumblrPinterestEmail Leave A Comment Cancel replyComment Save my name, email, and website in this browser for the next time I comment.