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

I now turn to a *subjective* consideration that belongs here; yet I can give even less distinctness to it than to the objective consideration just discussed, for I shall be able to express it only by image and simile. Why is our consciousness brighter and more distinct the farther it reaches outwards, so that its greatest clearness lies in sense perception, which already half belongs to things outside us; and, on the other hand, becomes more obscure as we go inwards, and leads, when followed to its innermost recesses, into a darkness in which all knowledge ceases? Because, I say, consciousness presupposes *individuality*; but this belongs to the mere phenomenon, since, as the plurality of the homogeneous, it is conditioned by the forms of the phenomenon, time and space. On the other hand, our inner nature has its root in what is no longer phenomenon but thing-in-itself, to which therefore the forms of the phenomenon do not reach; and in this way, the chief conditions of individuality are wanting, and distinct consciousness ceases therewith. In this root-point of existence the difference of beings ceases, just as that of the radii of a sphere ceases at the centre. As in the sphere the surface is produced by the radii ending and breaking off, so consciousness is possible only where the true inner being runs out into the phenomenon. Through the forms of the phenomenon separate individuality becomes possible, and on this individuality rests consciousness, which is on this account confined to phenomena. Therefore everything distinct and really intelligible in our consciousness always lies only outwards on this surface on the sphere. But as soon as we withdraw entirely from this, consciousness forsakes us―in sleep, in death, and to a certain extent also in magnetic or magic activity; for all these lead through the centre. But just because distinct consciousness, as being conditioned by the surface of the sphere, is not directed towards the centre, it recognizes other individuals certainly as of the same kind, but not as identical, which, however, they are in themselves. Immortality of the individual could be compared to the flying off at a tangent of a point on the surface; but immortality, by virtue of the eternity of the true inner being of the whole phenomenon, is comparable to the return of that point on the radius to the centre, whose mere extension is the surface. The will as thing-in-itself is entire and undivided in every being, just as the centre is an integral part of every radius; whereas the peripheral end of this radius is in the most rapid revolution with the surface that represents time and its content, the other end at the centre where eternity lies, remains in profoundest peace, because the centre is the point whose rising half is no different from the sinking half. Therefore, it is said also in the *Bhagavad-Gita*: *Haud distributum animantibus, et quasi distributum tamen insidens, animantiumque sustentaculum id cognoscendum, edax et rursus genitale* (xiii, 16, trans. Schlegel) [Undivided it dwells in beings, and yet as it were divided; it is to be known as the sustainer, annihilator, and producer of beings]. Here, of course, we fall into mystical and metaphorical language, but it is the only language in which anything can be said about this wholly transcendent theme.―from_The World as Will and Representation_. Translated from the German by E. F. J. Payne. In Two Volumes, Volume II, pp. 325-326

~ Arthur Schopenhauer

Metaphysics, a completely isolated and speculative branch of rational knowledge which is raised above all teachings of experience and rests on concepts only (not, like mathematics, on their application to intuition), in which reason therefore is meant to be its own pupil, has hitherto not had the good fortune to enter upon the secure path of a science, although it is older than all other sciences, and would survive even if all the rest were swallowed up in the abyss of an all-destroying barbarism. Reason in metaphysics, even if it tries, as it professes, only to gain *a priori* insight into those laws which are confirmed by our most common experience, is constantly being brought to a standstill, and we are obliged again and again to retrace our steps, as they do not lead us where we want to go. As to unanimity among its participants, there is so little of it in metaphysics that it has rather become an arena that would seem especially suited for those who wish to exercise themselves in mock fights, where no combatant has as yet succeeded in gaining even an inch of ground that he could call his permanent possession. There cannot be any doubt, therefore, that the method of metaphysics has hitherto consisted in a mere random groping, and, what is worst of all, in groping among mere concepts.What, then, is the reason that this secure scientific course has not yet been found? Is this, perhaps, impossible? Why, in that case, should nature have afflicted our reason with the restless aspiration to look for it, and have made it one of its most important concerns? What is more, how little should we be justified in trusting our reason, with regard to one of the most important objects of which we desire knowledge, it not only abandons us, but lures us on by delusions, and in the end betrays us! Or, if hitherto we have only failed to meet with the right path, what indications are there to make us hope that, should we renew our search, we shall be more successful than others before us?―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, p. 17

~ Immanuel Kant

A similar experiment may be tried in metaphysics as regards the *intuition* of objects. If the intuition had to conform to the constitution of objects, I would not understand how we could know anything of them *a priori*; but if the object (as object of the senses) conformed to the constitution of our faculty of intuition, I could very well conceive such a possibility. As, however, I cannot rest in these intuitions if they are to become knowledge, but have to refer them as representations, to something as their object, and must determine this object through them, I can assume either that the *concepts* through which I arrive at this determination also conform to the object, and I would again be as perplexed about how I can know anything about it *a priori*; or else that the objects, or what is the same thing, the *experience* in which alone they are known (as objects that are given to us), conform to those concepts. In the latter case, I recognize an easier solution because experience itself is a kind of knowledge that requires understanding; and this understanding has its rules which I must presuppose as existing within me even before objects are given to me, and hence *a priori*. These rules are expressed in *a priori* concepts to which all objects of experience must necessarily conform, and with which they must agree. With regard to objects, insofar as they are thought merely through reason and thought indeed as necessary, and which can never, at least not in the way in which reason thinks them, be given in experience, the attempts at thinking them (for they must admit of being thought) will subsequently furnish an excellent touchstone of what we are adopting as our new method of thought, namely, that we know of things *a priori* only that which we ourselves put into them.―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. 18-19

~ Immanuel Kant