The field of a science is an objectively closed unity: we cannot arbitrarily delimit fields where and as we like. The realm of truth is objectively articulated into fields: researches must orient themselves to these objective unities and must assemble themselves into sciences.
There is a science of numbers, a science of spatial figures, of animal species etc., but there are no special sciences of prime numbers, of trapezia, or of lions, nor of all three taken together.
If these are the themes of phenomenology, then it can also be called "science of consciousness," if consciousness be taken purely as such.
A new fundamental science, pure phenomenology, has developed within philosophy: This is a science of a thoroughly new type and endless scope. It is inferior in methodological rigor to none of the modern sciences. All philosophical disciplines are rooted in pure phenomenology, through whose development, and through it alone, they obtain their proper force.
Is not what was just described as immanent reflection simply identical with internal, psychological experience? Is not psychology the proper place for the investigation of consciousness and all its phenomena? However much psychology may previously have omitted any systematic investigation of consciousness, however blindly it may have passed over all radical problems concerning the bestowal, earned out in the immanence of consciousness, of objective sense, it still seems clear that such investigations should belong to psychology and should even be fundamental to it.
Along that way we now intend to walk together. In a quasi-Cartesian fashion we intend, as radically beginning philosophers, to carry out meditations with the utmost critical precaution and a readiness for any even the most far-reaching transformation of the old-Cartesian meditations. Seductive aberrations, into which Descartes and later thinkers strayed, will have to be clarified and avoided as we pursue our course.
This places two separate sciences in the sharpest of contrasts: on the one hand, phenomenology, the science of consciousness as it is in itself; on the other, the sciences of things, out, there as a totality.
Each I not only perceives, has not only experiences that posit intuitive existence, but also it has a more or less clear or confused knowledge; it thinks, it predicates and, as a scientific person, each I does science. Thereby, the I knows itself as one which sometimes judges correctly, one which sometimes falls into error, as one which occasionally succumbs to doubts and confusions, and also as one which occasionally presses on to clear conviction.
The aim of the meditations is a complete reforming of philosophy into a science grounded on an absolute foundation. That implies for descartes a corresponding reformation of all the sciences, because in his opinion they are only non-self sufficient members of the one all-inclusive science, and this is philosophy. Only within the systematic unity of philosophy can they develop into genuine sciences.
In earlier lectures I drew a distinction between positive and philosophical science. The fonner originates from the natural attitude of the mind, the latter from the philosophical.