The behaviour of the humanistic systems is too complex or too ill-defined to be analysed using definitive mathematics. In this paper we propose a method for the analysis of such systems using the concept of fuzzy sets. The methods for the manipulation of fuzzy variables are considered. These methods enable us to represent quantitatively the sum (or product) of fuzzy variables like large and small, and the convolution of fuzzy sequences. Since, while working with fuzzy variables, the data may become enormous, a technique for the data reduction is proposed. Using these techniques for the manipulation of fuzzy variables we are in a position to analyse fuzzy systems.