Abstract
The thesis that in social sciences causal explanations are possible only in terms o mechanisms due to the lack of genuine laws has been increasingly popular among social scientist and philosophers. In this article it is examined whether the explanation by mechanism is necessarily an explanation without laws or, on the contrary, it can involve some kind o laws. To this end it is argued, firstly, that mechanisms are not always the antonym of law insofar as they express propensities and so tendencies; secondly, that these tendencies ar causal and entail capacities and dispositions; thirdly, that capacities and dispositions involve in human behaviour have to face the problem of free will; and finally, reasons are offered i favor of considering causal tendencies as authentic laws. The ultimate aim of this article is to demonstrate that explanation of social facts can involve well-established laws in its explanans although they are not universal laws.