The symbolic paraphrase of 'because' sentences suggested by Frege, which is still widely accepted, will be gradually developed into a more adequate, though much more complicated, form. Out of the different types of such sentences, the 'for the only reason that' type will be given especial consideration. Furthermore, it will be expounded that contrary-to-fact conditionals may function either as 'for the only reason that' explanations, or as 'for at least the reason that' explanations, or as arguments, the difference being dependent (...) partly on certain temporal characteristics of their constituents and partly on the pragmatic features of the speech act situation. Consequently, counterfactuals have no definite logical structure, which is a reason, hitherto unnoticed, why they cannot be used in defining dispositional predicates. It will be shown, however, that 'for the only reason that' explanations can serve this purpose quite properly. (shrink)