Positivists regarded empirical observation freed of preconceptions as the means by which facts were obtained and explained. This view, however, has been greatly contested since the Vienna Circle’s avid pursuance of it. The main problems include its inability to be checked and criticised by the scientific community members. In other words, they are subjective, fallible and thus unreliable.  It is this initial discontent with positivism, especially with logical positivism which prompted Karl Popper to develop his Theory of Falsifiability, a theory which no longer relies on induction but on deduction, which accepts that truth is not attainable and which casts theories aside which have been refuted by only a single piece of empirical evidence. Falsification is also a demarcation between science and non-science, something which has proved to be very controversial. Thomas Kuhn, perhaps the most well known critic of Popper’s work, does not believe in induction or deduction as methods through which science progresses. Instead, he introduces the concept of normal science, revolutionary science and paradigms. The differences between these two men’s work will be analysed, the implications of each for the conduct of social sciences commented upon and the work of Imre Lakatos, a twentieth century philosopher of mathematics and science, highlighted in order to illustrate just how much both philosophers resonate in the social sciences as a whole.