An invalid contingency argument on SEP
Bruce Reichenbach wrote the SEP article on cosmological arguments. SEP articles are, I believe, peer-reviewed, and so we shouldn't expect them to contain invalid arguments. This one does, however. Here it is: (1) A contingent being (a being such that if it exists, it could have not-existed or could cease to exist) exists. (2) This contingent being has a cause of or explanation for its existence. (3) The cause of or explanation for its existence is something other than the contingent being itself. (4) What causes or explains the existence of this contingent being must either be solely other contingent beings or include a non-contingent (necessary) being. (5) Contingent beings alone cannot provide a completely adequate causal account or explanation for the existence of a contingent being. (6) Therefore, what causes or explains the existence of this contingent being must include a non-contingent (necessary) being. (7) Therefore, a necessary being (a b...