But there is also an _a priori_ aspect of thought, where by a mediation, not made by anything external but by a reflection into self, we have that immediacy which is universality, the self-complacency of thought which is so much at home with itself that it feels an innate indifference to descend to particulars, and in that way to the development of its own nature. It is thus also with religion, which, whether it be rude or elaborate, whether it be invested with scientific precision of detail or confined to the simple faith of the heart, possesses, throughout, the same intensive nature of contentment and felicity. But if thought never gets further than the universality of the Ideas, as was perforce the case in the first philosophies (when the Eleatics never got beyond Being, or Heraclitus beyond Becoming), it is justly open to the charge of formalism. Even in a more advanced phase of philosophy, we may often find a doctrine which has mastered merely certain abstract propositions or formulae, such as, 'In the absolute all is one,' 'Subject and object are identical,'--and only repeating the same thing when it comes to particulars. Bearing in mind this first period of thought, the period of mere generality, we may safely say that experience is the real author of _growth_ and _advance_ in philosophy. For, firstly, the empirical sciences do not stop short at the mere observation of the individual features of a phenomenon. By the aid of thought, they are able to meet philosophy with materials prepared for it, in the shape of general uniformities, _i.e._ laws, and classifications of the phenomena. When this is done, the particular facts which they contain are ready to be received into philosophy. This, secondly, implies a certain compulsion on thought itself to proceed to these concrete specific truths. The reception into philosophy of these scientific materials, now that thought has removed their immediacy and made them cease to be mere data, forms at the same time a development of thought out of itself. Philosophy, then, owes its development to the empirical sciences. In return it gives their contents what is so vital to them, the freedom of thought,--gives them, in short, an _a priori_ character. These contents are now warranted necessary, and no longer depend on the evidence of facts merely, that they were so found and so experienced. The fact as experienced thus becomes an illustration and a copy of the original and completely self-supporting activity of thought.