Our conduct of the ontological investigation in the first and second parts opens up for us at the same time a view of the way in which these phenomenological investigations proceed. This raises the question of the character of method in ontology. Thus we come to the third part of the course: the scientific method of ontology and the idea of phenomenology. The method of ontology, that is, of philosophy in general, is distinguished by the fact that ontology has nothing in common with any method of any of the other sciences, all of which as positive sciences deal with beings. On the other hand, it is precisely the analysis of the truth-character of Being which shows that Being also is, as it were, based in a being, namely, in the Dasein. Being is given only if the understanding of Being, hence the Dasein, exists. This being accordingly lays claim to a distinctive priority in ontological inquiry. It makes itself manifest in all discussions of the basic problems of ontology and above all in the fundamental question of the meaning of Being in general. The elaboration of this question and its answer requires a general analytic of the Dasein. Ontology has for its fundamental discipline the analytic of the Dasein. This implies at the same time that ontology cannot be established in a purely ontological manner. Its possibility is referred back to a being, that is, to something ontical―the Dasein. Ontology has an ontical foundation, a fact which is manifest over and over again in the history of philosophy down to the present. For example, it is expressed as early as Aristotle's dictum that the first science, the science of Being, is theology. As the work of the freedom of the human Dasein, the possibilities and destinies of philosophy are bound up with man's existence, and thus with temporality and with historicality, and indeed in a more original sense than is any other science. Consequently, in clarifying the scientific character of ontology, *the first task is the demonstration of its ontical foundation* and the characterisation of this foundation itself.―from_The Basic Problems of Phenomenology_

~ Martin Heidegger

Thus with the question of the Being of truth and the necessity of presupposing it, just as with the question of the essence of knowledge, an 'ideal subject' has generally been posited. The motive for this, whether explicit or tacit, lies in the requirement that philosophy should have the '*a priori*' as its theme, rather than 'empirical facts' as such. There is some justification for this requirement, though it still needs to be grounded ontologically. Yet is this requirement satisfied by positing an 'ideal subject'? Is not such a subject *a fanciful idealization*? With such a conception have we not missed precisely the *a priori* character of that merely 'factual' subject, Dasein? Is it not an attribute of the *a priori* character of the factical subject (that is, an attribute of Dasein's facticity) that it is in the truth and in untruth equiprimordially?The ideas of a 'pure I' and of a 'consciousness in general' are so far from including the *a priori* character of 'actual' subjectivity that the ontological characters of Dasein's facticity and its state of being are either passed over or not seen at all. Rejection of a 'consciousness in general' does not signify that the *a priori* is negated, any more than the positing of an idealized subject guarantees that Dasein has an *a priori* character grounded upon fact.Both the contention that there are 'eternal truths' and the jumbling together of Dasein's phenomenally grounded 'ideality' with an idealized absolute subject, belong to those residues of Christian theology within philosophical problematics which have not as yet been radically extruded.The Being of truth is connected primordially with Dasein. And only because Dasein is as constituted by disclosedness (that is, by understanding), can anything like Being be understood; only so is it possible to understand Being.―from_Being and Time_. Translated by John Macquarrie & Edward Robinson, p. 272

~ Martin Heidegger

Human existence can relate to beings only if it holds itself out into the nothing. Going beyond beings occurs in the essence of Dasein. But this going beyond is metaphysics itself. This implies that metaphysics belongs to the nature of man. It is neither a division of academic philosophy nor a field of arbitrary notions. Metaphysics is the basic occurrence of Dasein. It is Dasein itself. Because the truth of metaphysics dwells in this groundless ground it stands in closest proximity to the constantly lurking possibility of deepest error. For this reason no amount of scientific rigor attains to the seriousness of metaphysics. Philosophy can never be measured by the standard of the idea of science.If the question of the nothing unfolded here has actually questioned us, then we have not simply brought metaphysics before us in an extrinsic manner. Nor have we merely been transposed to it. We cannot be transposed there at all, because insofar as we exist we are always there already. For by nature, my friend, man's mind dwells in philosophy (Plato, Phaedrus, 279a). So long as man exists, philosophizing of some sort occurs. Philosophy―what we call philosophy―is metaphysics getting under way, in which philosophy comes to itself and to its explicit tasks. Philosophy gets under way only by a peculiar insertion of our own existence into the fundamental possibilities of Dasein as a whole. For this insertion it is of decisive importance, first, that we allow space for beings as a whole; second, that we release ourselves into the nothing, which is to say, that we liberate ourselves from those idols everyone has and to which he is wont to go cringing; and finally, that we let the sweep of our suspense take its full course, so that it swings back into the basic question of metaphysics which the nothing itself compels: 'Why are there beings at all, and why not rather nothing?'―from_What is Metaphysics?_

~ Martin Heidegger

Our critique is not opposed to the *dogmatic procedure* of reason in its pure knowledge as science (for science must always be dogmatic, that is, derive its proof from secure *a priori* principles), but only to *dogmatism*, that is, to the presumption that it is possible to make any progress with pure (philosophical) knowledge from concepts according to principles, such as reason has long been in the habit of using, without first inquiring in what way, and by what right, it has come to posses them. Dogmatism is therefore the dogmatic procedure of pure reason, *without a preceding critique of its own powers*; and our opposition to this is not intended to defend that loquacious shallowness which arrogates to itself the name of popularity, much less that skepticism which makes short work of the whole of metaphysics. On the contrary, our critique is meant to form a necessary preparation in support of metaphysics as a thorough science, which must necessarily be carried out dogmatically and strictly systematically, so as to satisfy all the demands, no so much of the public at large, as of the Schools. This is an indispensable demand for it has undertaken to carry out its work entirely *a priori*, and thus to carry it out to the complete satisfaction of speculative reason. In the execution of this plan, as traced out by the critique, that is, in a future system of metaphysics, we shall have to follow the strict method of the celebrated Wolff, the greatest of all dogmatic philosophers. He was the first to give an example (and by his example initiated, in Germany, that spirit of thoroughness which is not yet extinct) of how the secure course of a science could be attained only through the lawful establishment of principles, the clear determination of concepts, the attempt at strictness of proof and avoidance of taking bold leaps in our inferences. He was therefore most eminently qualified to give metaphysics the dignity of a science, if it had only occurred to him to prepare his field in advance by criticism of the organ, that is, of pure reason itself―an omission due not so much to himself as to the dogmatic mentality of his age, about which the philosophers of his own, as well as of all previous times, have no right to reproach one another. Those who reject both the method of Wolff and the procedure of the critique of pure reason can have no other aim but to shake off the fetters of *science* altogether, and thus to change work into play, certainty into opinion and philosophy into philodoxy. ―from_Critique of Pure Reason_. Preface to the Second Edition. Translated, edited, and with an Introduction by Marcus Weigelt, based on the translation by Max Müller, pp. 28-29

~ Immanuel Kant