Ideas fundamental of the positive philosophy of Comte: To – the law of the three states; according to Comte the human thought has happened through three states: the 1) theological one (in which the phenomena are explained, by the intervention of supernatural forces), 2) the metaphysician (the phenomena are explained by the intervention of abstract forces), and 3) the positive (in which the men resign to explain the intimate essence of the phenomena and they limit themselves to find his laws). B- Classification of sciences; Comte classifies sciences to show the unit of the human thought. In the classification he makes only enter only theoretical sciences, because the practices are classified according to the theoretical ones and within the theoretical ones, to the abstract ones, because the concrete ones follow the classification of the abstract ones. Fundamental abstract sciences are: mathematical, astronomy, physics, chemistry, Biology, sociology; this one classification is based on a double criterion: logical historical. Logical criterion: the first classifications are simplest, most general and most abstract. The last ones are most complex, less general and most concrete. The classification follows an origin of decreasing majority and increasing complexity.
The study of the most complex phenomena, supposes already constituted the study of simplest. So that the physics can become a science, it is precise that astronima has been constituted before. Historical criterion: sciences are placed in the order of their entrance to the positive state. If there is cienias fundamental that they are those that we enumerated, it is because there are six orders of different phenomena. If there is a chemical science different from a physical science, is because the chemical phenomena have characters differentiate that them from the physical phenomena and that make of them a different order of phenomena. Each order has own characteristics and require without damages to lean in the others, certain concepts or own ideas.