Arnaud Bailly kindly exposed my mistake: I cited Leibniz Monadology attributing it to Spinoza. Call me idiot but it wasn't thoughtless mistake, I really mixed up Spinoza's concept of 'modes' with Leibniz's concept of 'monad'. But it is because of my laziness rather than foolishness (at least this time). My argument is that in his final writings Leibniz's 'monads' encompass reality as perceptions and emanate from God as thought emanates from the mind, which is exactly what Spinoza's 'modes' are about. So monads and modes being equal I prefer Spinoza as a patron for Haskell for his purity of cause-effect treatment. Arnold adds another Haskell-Spinoza nicety, I hope he won't mind my including his all letter. Thank you Arnold, it is encouraging to find guys like you. Philosophy is not my thing but I believe every man should tackle it as exercise. Hello Andrzej, Thanks a lot for your bit of rationalism among all these devotions :-) I think however that you are confusing Spinoza with Leibniz in the following assertion. Monads are a concept invented by the latter, together with the famous "the best possible world ever" mocked by Voltaire in "Candide". The comparison between Haskell and spinozism is rather interesting though, especially when one considers that Spinoza's "Ethic" is based on the idea that the ultimate goal of one self is to increase its power to live, an affect which it calls "Joy". Thinking of Haskell as a way to increase one's joy and one's power is a nice thought. Regards, Arnaud Bailly