We investigate whether there can be scientific truth if this truth depends ’inter alia’ on a true causal principle and if the principle strictly implies ’nature’s God’ ’qua’ a ’first cause’. If there is this ’cause’, then how does one know whether it or a natural cause was the cause of a phenomenon? Responses to this question involve examining critiques of the causal principle by Hume and Kant as well as by distinguishing logical from physical possibilities.