The reasoning that a necessary being can only give rise to a necessary universe confuses logical implication with causal link.
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« Some philosophers (Sartre, for example) argue that if the contingent universe had its raison d'être in a necessary being, it would itself be necessary. For, they say, propositions deduced from necessary propositions are also necessary (if it is necessary for P that P implies Q, then it is necessary for Q). [...] Here, there is a confusion between logical implication and causal link. Requiring an ultimate necessary cause in no way implies that it must cancel out the contingency of the universe by providing a deductive explanation. [...] The first cause does not imply the universe. It causes it, which is different. »
Frédéric Guillaud, God exists, p.197, Éditions du Cerf, Paris, 2013
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