Now Comte saw in himself, as in his contemporaries, two general methods, two “modes of thought” which cannot coexist without contradiction, although neither one nor the other has obtained a full mastery up to the present time. Concerning several categories of phenomena he thinks as a scholar trained in the school of Hobbes, of Galileo, of Descartes and of their successors. He does not seek to explain them by causes. When, by means of observation or deduction, he has arrived at a knowledge of their laws he remains satisfied. For the knowledge of these laws allows him in certain cases to intervene in the phenomena, and to substitute to the natural order an artificial order better suited to his requirements. It is thus that mechanical, astronomical, physical, chemical and even biological phenomena are objects of _relative_ and _positive_ science for him to-day. But, as soon as the question is one of facts which originate in the human conscience, or which are connected with social life and with history, an opposite tendency becomes predominant. Instead of solely seeking for the laws of phenomena, our mind desires to explain them. It wants to find the essence and the cause. It speculates upon the human soul, upon the relation of that soul to the other realities of the universe, upon the end which society should have in view, upon the best possible government, upon the social contract, etc. All these questions arise from the “metaphysical” mode of thought, and this mode is formally incompatible with the preceding one. Yet we see both of them subsisting in our minds to-day. Social dynamics will show how this condition must have been produced. But whatever the historical reasons may be, the reality is only too evident. The human mind to-day can neither adhere entirely to nor give up entirely one or the other of these two modes of thought. Undoubtedly it feels that the conquests of positive science are “irrevocable.” For example, how could it return to a metaphysical or theological explanation of astronomical or physical phenomena? But, on the other hand, metaphysical and theological conceptions seem to it no less indispensable. It does not believe it could do without them. And this is natural. For, to satisfy the desire for unity, which is its supreme requirement, the human mind demands a conception of the whole which embraces all the orders of phenomena, what Kant called a totalizing of experience, in a word a “philosophy.”