This chapter presents the criteria that sociological explanations and theories must cover and their role in empirical research based on quantitative methods. These criteria are: (1) must regain the phenomenon's intrinsic causality; (2) must reconstruct the conditions in which a social phenomenon surges and develops, although a historical methodology is insufficient in many cases; (3) must develop a second-order observation. Empirical sociological research that resorts to the quantitative method is among first-order observations. The second-order research are those that makes the first-order observations their subject of observation, which is why sociology, unlike other sciences, is a discipline that has itself as object of study (the sociology of sociology); and (4) must separate the intentions of the actors' actions from their effects. The first-order observation based solely on establishing statistical relationships, such as those performed by sociobiology, can offer the appearance of high scientific validity. In its last part, this chapter offers an example of the need to complete or reject data with second-order theoretical observations.